Tag Archives: common grammar mistakes

Common Grammar Mistakes: Let’s versus Lets.

Common Grammar Mistakes: Let's versus Lets. (From jdeeringdavis on Flickr.)

This week, while working with a number of students on their final papers and transfer essays, a particular grammar question popped up. Well, to say it “popped up” is a bit of an understatement; this question came from not one, but SIX students, separately, yet almost all on the same day. (Travis, you broke up the would-be flash mob. Shame on you.)

So, because my students have assumed a Voltron-like formation to ask me the same, exact question (!), I will answer it here.

What is the difference between let’s and lets?

“To let” means to allow or to permit, as in “I let the dogs out each morning.” It also means to lease or rent, as in “Wanted: Apartment to let” but let’s (HA!) not get ahead of ourselves here.

“Lets,” then, is the third person singular present tense form of “to let.” Translation: you use it with he, she, or it when using the present tense, like this: “Sally lets her brother use her bicycle on weekends.”

Easy enough, right? Now, for the second part.

“Let’s,” with an apostrophe, is a contraction of “let” and “us.” It is commonly used in first personal plural commands, like “Let’s go!” or “Let’s eat!” For the less enthusiastic, “let’s” commands without exclamation points suffice as well.

As a contraction, “Let’s go!” really means “Let us go.” This contraction, like most others, is more informal– after all, trips to the grocery store don’t have to be quite so dramatic.

Here’s another example of what I mean: “Guys, let’s go to the beach.” In reality, you’re really saying “Guys, let us go to the beach,” albeit in a less formal, contracted way.

So, therein lies the difference: “Lets” is a third person singular conjugation of the word “let,” as in, “She lets me watch sports” or “It lets you download more information.” “Let’s,” in turn, is the contraction of “let” and “us,” used in plural commands, such as “Let’s get started” or “Let’s get married.”

A good rule of thumb:
To ensure you’re using the proper form of “let’s,” substitute “let’s” with “allow us” when constructing a command. It’s an extra step but, by keeping this in mind, you’ll be sure to choose to right form.

Here’s what I mean:

With “let’s”: Let’s grab some sushi.
With “allow us”: Allow us [to] grab some sushi.

This makes sense, right? It may be overly formal, but it’s nonetheless grammatically sound. Of course, you don’t actually have to substitute “let’s” with “allow us” in your writing; however, by keeping this in mind, you will know (and use!) the correct choice.

And, that’s it. Once you know the difference, it’s easy to remember. Granted, I don’t have a funny mnemonic this time around (sorry!), but it’s relatively easy to keep these two straight.

Common Grammar Mistakes: Which versus That.

Which versus That. (From-Paul V8 on Flickr.)

Knowing the difference between which and that can be a bit confusing. Which one do you use? That one? Okay, I’ll stop.

What makes matters worse is that there has been a shift in usage and definition over the last century. While you may not be using grammar books from 100 years ago, you’re more likely to encounter this change in literature as so many classics are over a century old.

So, which one do you use, and how can you tell the difference?

Ultimately, it boils down to the difference between two types of clauses.– restrictive and non-restrictive. A restrictive clause is one that limits or restricts the scope of the noun it is referring to. A non-restrictive clause, as I’m sure you can imagine, doesn’t. Here is what I mean:

The cheese that is stinky is delicious.
The cheese, which is stinky, is delicious.

In the first example, the clause “that is stinky” is a restrictive clause, because it limits the scope of the word “cheese”, as it is only referring to the cheese that is stinky. It isn’t referring to any other cheese except that one. If you remove the clause, you are only left with: “The cheese is delicious.” Without the clause, the reader no longer knows which cheese is being referred to and the sentence loses crucial information– not just any cheese is delicious.

In the second example, the clause is non-restrictive: the cheese’s stinkiness is additional information about a cheese being described. Basically, the clause which is stinky is here parenthetical —as in, “by the way, the cheese happens to be stinky.” It is an additional piece of information but it’s not essential to the sentence’s meaning.

Here’s another example:

Another great type of cheese is one that is blue-veined and harder than most.

The clause “that is blue-veined and harder than most” modifies and constrains “one”. Another great type of cheese is not just any other cheese but one particular type. The clause is restrictive,especially considering how little sense the sentence would make without it.

In terms of punctuation, there are two hard-fast rules to follow:

  • Restrictive clauses are not separated from the rest of the sentence by commas.
  • Non-restrictive clauses must be separated by commas from the rest of the sentence to indicate parenthesis.

This all seems fairly simple, yes?

Of course, I can’t end this blog post without listing a few exceptions to complicate things a bit. I don’t know about you, but I can certainly think of a few examples that defy the rules I’ve listed above, yet still make perfect sense. In fact, few writers have ever followed these rules systematically, and it’s easy to find examples where either relative pronoun is used with restrictive clauses. Here’s an example:

A vase which has lost its bottom is useless.

The clause which has lost its bottom is certainly restrictive; without it, you’re left with “A vase is useless” which you can agree makes no sense. Now, according to the traditional rules, which should instead be that. However, did you have any trouble discerning the sentence’s meaning? I’m guessing the answer is no.

It also comes down to a question of style. Granted, style is a bit harder to pin down as “it just sounds better” is hard to define as preferences to consonant stress and rhythm. (For the linguist geeks in the house, that provides a softer, relatively unstressed sound while which is harder and easier to stress.) . But, in certain instances, it does “just sound better” to use that instead of which. Here are a few examples; again, they don’t necessarily abide by the rules, but they are definitely points to keep in mind.

  • In clauses that follow impersonal constructions, such as it is, that is preferred: “It was the plant that fell”.
  • Clauses that refer  to the words anything, nothing, something, or everything have a slight preference for that over which: “Can you think of anything that still has to be done?”
  • Clauses that follow a superlative also tend to prefer that: “Thank you for the best night that I’ve ever had”.

By throwing these wrenches in, I’m not suggesting to completely ignore what I just said. After all, if that were the case, I would just delete this blog post entirely. What I am suggesting, however, is that language is fluid– yes, there are rules, but sometimes you can bend them a little– and you CAN use which instead of that sometimes, so long as your meaning is well-understood.

That being said, it doesn’t apply the other way around; non-restrictive clauses should always to start with which. That’s just the way it is. Likewise, the punctuation rules will always apply– non-restrictive clauses always need commas, but restrictive ones (whether you use that or which) don’t. Without the proper punctuation, your whole sentence can go awry and your meaning could get totally lost. So, if you do decide to bend the rules, you have to do so carefully. If you’re not sure (and it’s understandable if you’re not), then just follow the restrictive/non-restrictive rules I’ve first outlined above and you’ll be fine.



Common Grammar Mistakes: Fewer versus Less

Common Grammar Mistakes: Fewer versus Less. (By Jennifer Peyton from Flickr.)

So, for today’s grammar topic, I’m covering the difference between fewer and less.

Now, less and fewer pretty much mean the same thing—they both mean the opposite of more. So, what’s the problem?

Well, what differentiates these two is not their definition, but the types of nouns that they are used to describe. At its most basic, the rule is that you use less with mass nouns and fewer with count nouns.

Count nouns are, well, things that you can count. Whether they are books, pens, or Skittles, these are all things that can be counted individually. So, if you can count them, it’s a count noun which means it belongs with fewer, as in, “You should eat fewer Skittles.”

Mass noun, on the other hand, are nouns that describe things that can’t be counted individually. These can’t be pluralized– for example, rice, dust, or wool are all mass nouns, all words that can’t be made plural. Because these things can’t be counted individually, so they are described with the word less. For example: “If I had less dust in my house, I wouldn’t sneeze as much.” This clearly makes much more sense than “If I had fewer dusts in my house.” So, if you have difficulty pluralizing the word — the words clutter, leather, and cloth are more examples– then this signifies that it is a mass noun.

Sometimes, however, determining certain words as being either count nouns or mass nouns can be a bit confusing. For example, coffee or soda can be either count nouns or mass nouns depending on how they are referred to. For instance, if you are making coffee, it is a liquid that can’t be quantified– so, if the coffee pot overflows, you need to make less coffee next time. Yet, if you’re a barista making cups of coffee as a barista, you may need to serve fewer coffees if patrons decide to leave. Of course, the noun that is actually being count is the word cups — the cups are being counted, not the coffee itself– but, it is common to refer to a cup of coffee as just “a coffee” and so this distinction must be clear. Mass nouns (like coffee) can’t be made plural but, in this case, it can be made into a count nounI’ve made a mass noun plural, but in the process I transformed it into a count noun.

Another tricky noun is the word furniture; it isn’t immediately obvious whether it is a mass noun or a count noun. Like coffee, it is technically a mass noun, even though it can describe multiples of count nouns– there can be countable pieces of furniture, but furniture itself is a collective name for a mass of stuff. You could say, “There are too many places to sit; we need fewer couches,” but you would never say, “we need fewer furnitures.”

Of course, we can never be without exceptions. For instance, it is customary to use the word less to describe time, money, and distance. Yes, they are quantifiable, but they require less rather than fewer: “The flight time is less than two hours so I hope to pay less than $350 per ticket.” But, aside from time, money, and distance, the rules I stated above remain the same.

So, now that we’ve gotten count nouns and mass nouns straightened out, let’s finish up by clarifying a very important fact: Most signs for supermarket express lanes are wrong. As you know, most of the signs for these lanes read, “10 items or less.” Now you know that these are grammatically incorrect and should instead read, “10 items or fewer.” Why? Because, of course, items are individual, countable things. As such, they are count nouns which means it uses the word fewer. Why this mistake is made in practically every grocery store and supermarket is beyond me but, at the very least, now you know the difference.


Common Grammar Mistakes: A versus An.

A or an?

This question came up earlier this week and, well, here I am to save the day. Most have learned that you use a before words that start with consonants and use an before words that start with vowels. However, it’s actually a bit more complicated than that.

The rule actually is that you use a before words that start with a consonant sound and an before words that start with a vowel sound.

The question at hand was actually regarding the word “hour” and whether an hour is correct as opposed to a hour. To answer this question specifically, an hour is correct, because hour starts with a vowel sound.

Words that begin with h or u are most confusing because these words can start with either vowel sounds or consonant sounds, regardless of whether a consonant or vowel is actually being used. For example, it is a historic moment because historic starts with an h sound (the h in “h-h-hey!”) but he’s an honorable fellow because honorable starts with an o sound. Similarly, it is a Utopian idea (“you”-topian”), but an unfair world (“uh-nfair”).

The letters o and m can be tricky too, for the same reasons. For example, you would use aif you were to say, “She has a one-track mind,” because one-track starts with a w sound. Similarly, “She has an MBA, but chooses to work as a missionary.”

One complication is when words are pronounced differently in British and American English. For example, the word for a certain kind of plant is pronounced “’erb” in American English and “herb” in British English. So the proper form in America is an (h)erb, and the proper form in Britain is a herb. In the rare cases where this is a problem, use the form that will be expected in the vernacular of the country in question.

I know this seems confusing –I’m sure way more confusing than originally thought!– but, remember: it is the sound that governs whether you use a or an, not the actual first letter of the word.

Common Grammar Mistakes: Double negatives.

“Why are double negatives so bad?”

I was asked this question recently by a student, and I decided to answer it here.

Double negatives often amount to much confusion– not because of misconstrued usage like lay and lie or affect and effect, but because of misplaced meaning. Like dangling participles, double negatives create ambiguity within a statement, potentially confusing the reader.

Wait, I still don’t get it; what’s a double negative?

A double negative is where two forms of negation are used in the same sentence. When this happens, the negation in the sentence isn’t intensified or made “double-bad”– it is instead made positive.  In essence, two wrongs do make a right, in the case of double negatives anyway. For those of you who know formal logic, this will sound very familiar to you. There are exceptions, but, unless your writing in a foreign language, they does not apply here: in languages like French or Spanish, the use of double negatives do mean something is super-ultra-mega-bad but, in English, it does not.

Here are a few examples of double negatives:

  • I don’t not love you
  • I can’t get no satisfaction
  • We ain’t got no history
  • We don’t need no education

In these examples, the double negative creates an opposite meaning: the two negatives cancel each other out and form a positive sense.  So, “I don’t not love you” becomes “I don’t not love you,” and “we ain’t got no history” really means “we ain’t got no history.” Aw.

Of course, double negatives can sometimes be used creatively, such as in advertising; when “Nobody doesn’t like Sara Lee” is sung, what’s being implied is that everybody likes Sara Lee. However, even in creative use, double negatives can lead to some confusion: is Pink Floyd really calling for thought control? Is Mick Jagger really asserting his ability to in fact gain satisfaction, as opposed to, well, not getting any?

As such, the double negative is, generally speaking, to be avoided– that is, unless you’re using it within a creative context. Who knows what Roger Waters was going for but, at the very least, be mindful of it yourself.


Common Grammar Mistakes: Affect versus Effect.

Affect and effect are so often confused, they are practically the original common grammar mistake. They are misconstrued nearly every which way, everywhere,  on a nearly daily basis. Of course, all these errors are easily avoidable, and here’s how.

First, you have understand the intrinsic differences between these two words. For the most part, this difference is actually pretty straightforward: one is commonly used as a verb (affect) and one is commonly used as a noun (effect). Easy, right? These two can actually be switched but let’s start with the basics first.

Affect, as a verb, means to influence, as in “My recent lottery win has affected my spending habits greatly” or “His recent knee surgery affected his gait.”

Effect, as a noun, means a result, as in “My recent lottery win had a clear effect on my spending habits” or “His recent knee surgery had an obvious effect on his gait.”

Here’s an easy way to tell them apart:

An Affect is  an Action, but an Effect is an End result.

Awesome, right? Now, let’s move on.

Rare uses of Affect and Effect

So, I hinted above that these two can be used differently than how I had previously explained.  In rare instances, they can, in particular circumstances.

In psychology, affect can be used as a noun– as in, “She displayed a happy affect.” This definition is used in psychology to signify the difference between knowing a person’s mood really is and knowing what their mood appears to be. Meaning, it’s hard to discern whether the person (or, really, patient) is actually happy or just appearing to be happy. In psychology, this difference is important.

Effect, in turn, can be used as a verb, meaning to bring about, cause, or accomplish. For example: “The President hoped this new program would effect change.” Here, effect is used as a noun. Here is another example: “Andy effected his escape from prison with a rock hammer and a carefully placed poster.” Of course, this usage is less common; it is used predominantly in political writing and journalism.

Like most common grammar mistakes, these two words seem confusing but, with a little thought and maybe a memory trick or two, they’re actually very easy to tell apart.

Common Grammar Mistakes: Who and Whom.

Common Grammar Mistakes: Who versus Whom.

Okay, guys. I’m about to embark on one of the most confusing aspects of grammar and word choice. It is mistaken so often, I would have go into spasms if I even attempted to address it at every encounter. Alas, this is a daily struggle. So, with that, I will describe the differences between who and whom, how to use them, and, most importantly, how to avoid mistakes. First, in order to fully understand the differences between these two, we also must discuss the differences between subjects and objects. I have covered this in previous grammar posts but  here is a brief refresher for you. To help remember the differences between subject and object, you can use this interesting mnemonic:

I love you; you are the object of my affection.

Aw, how sweet. This mnemonic works in two ways, both of which describe subject and object pretty clearly. I, in this sentence, is the subject and is in the active voiceI is doing the loving here. You, on the other hand, is the receiver of this action, making this the object. This fact, of course, is further clarified by the mnemonic: You are the object of my affection. Quite literally, you is the object of I‘s affection. Such is love. Okay, moving on. Who and whom both function as pronouns but, in operation, they differ from each other much like subjects and objects do. Who operates as a subject– it is the I of the above mnemonic. Whom, in turn, operates as the object– the you. As such, their usage has to follow these functions; who completes the action and whom is the receiver. Here are some examples: Who stole my cheese? : The who, in this instance, is the one allegedly stole my cheese. Therefore, it is the subject. From whom did you steal that cheese? : Here, whom functions as the one who the cheese was stolen from; it is the receiver of the action,  steal. Therefore, it is the object. Following this, use whom when you are referring to the receiving object. So, the question “who do you think you are?” is correct. But, the questions “Who do you love?” and “Who do you voodoo?” are not. Another easy way to remember is to think of the answers to these questions and how they would relate to he or him Meaning, when I ask “From whom/who did you steal that cheese?” and you answer “from him,” then you know to use whom. Similarly, if you ask “Who/whom does he think he is?” and you answer “he think he’s the cat’s pajamas,” then you know to use who. Just remember: the –m in him should correspond with the -m in whom.

Common grammar mistakes: Dangling participles.

Common Grammar Mistakes: Dangling Participles. (From OptimumCareer on Flickr.)

As an editor, I have a number of literary and textual pet peeves. Surprisingly (or, perhaps not?), lolspeak is not one of them. But, in any case, some things just drive me and every other like-minded nerd insane. One of things includes dangling participles. To review, a participle is a verb pretending to be an adjective. Usually, this is a verb in its -ing form. For example, the word run is normally a verb, but add an -ing ending and it can become an adjective. So, when you say “I run every morning,” it’s a verb. But, it can also be an adjective: “I forgot my running shoes this morning.” The word run went from verb to adjective, which also forms your present participle.

So, now you understand participles. Good. Now, we move on to participial phrases.

Participial phrases are phrases that include, you guessed it, participles. These phrases are meant to modify the subject of the sentence. For example: “Drinking my coffee, I thought of an example of participial phrases.” Drinking my coffee” modifies the subject, “I,” with “drinking” as the participle.

Another example would be: “Stifling a yawn, I shuffled off to make more coffee.” “Stifling a yawn” is the participial phrase, modifying the subject, “I” (yet again). “Stifling,” of course, serves as the participle.

Okay, with all that said, dangling participles are participial phrases that are left with nothing to modify. Meaning, they are supposedly there to modify the subject, except the subject doesn’t agree with its modifier.

You might ask how this is possible. Well, here’s an example: “Drinking my coffee, the coffee-maker had shut off.” As you can imagine, this does not make sense. “Drinking my coffee” should modify… the coffee-maker? No. The coffee-maker is not drinking my coffee, I am. So, where am I? Hence, the reason these errors are called dangling participles– so sad and alone, without a subject to modify.

There are ways to fix this, of course. Instead of “Drinking my coffee, I noticed the coffee-maker had shut off.” Now, “drinking my coffee” is modifying the correct subject and–there I am!– the coffee is being drunk by me this time, not the coffee-maker.

One handy way to make sure you don’t make this mistake is to put a silent “while” before any participial phrases. So, “Drinking my coffee, I noticed the coffee-maker had shut off” becomes “While drinking my coffee, I noticed the coffee-maker had shut off.” Using the word “while” will emphasize what the modifying participle is doing, which will then remind you that the subject should agree with this action. If it’s more helpful for you to actually begin the phrase with “While…” rather than just with the participle, that’s fine, too. Just be mindful of who is doing what and what should be modifying whom.

So, to be clear:

“Drinking my coffee, I noticed the coffee-maker had shut off.” This is good.

“While drinking my coffee, I noticed the coffee-maker had shut off.” This is also good.

“Drinking my coffee, the coffee-maker had shut itself off.” This is bad.

“While drinking my coffee, the coffee-maker was gone.” Even worse.





Common grammar mistakes– Lay versus lie.

In many of my grammar posts, I often discuss common but misused words like it’s versus its or I.e versus E.g.. So, for this week’s installment, I’ll be covering the differences between lie and lay, probably the most misconstrued of all.

The most barebones difference between lie and ‘lay’ is that ‘lay’ requires a direct object. Going back to third grade, direct objects follow transitive verbs or action words. They are the “what?” and “who?” of the “subject+verb” equation. As in:

Jenny(subject) + played(verb)+WHAT?” Answer, soccer (direct object).

So, lay needs something or someone to do the laying– for instance, “Lay your book on the table.” Of course, as a command, the subject is the invisible ‘you’ and the sentence can be diagrammed as follows:

(You, subject) + Lay(action verb) + your book (direct object) +on the table (prepositional phrase, but more on this later)

Lie, on the other hand, does not require a direct object. So, if you want to lie down on the couch, you’re free to do so. Please note: “on the couch” is NOT a direct object (yet another prepositional phrase, more on that later) as the couch is not doing the lying down, you are the one doing it. Okay, get up now.

Sounds easy, right?

Here’s an easy way to remember:

Fans of older music will be shocked to know that both Bob Dylan and Eric Clapton are wrong: “Lay, lady, lay” should be “Lie, lady, lie“, and “Lay down, Sally” should be “Lie down, Sally”. Yet, Kelly Rowland, in all her pop-princess glory, is totally right with “Lay it on me“. Well, that’s music for you.

The present participles of these verbs aren’t so bad, either. As a reminder, participles are part of the perfect tenses– they are the latter half of verb phrases with am, has/has been, and have/have been in them.

The present tense of lie is lying— as in, “I’m lying down on the couch right now; it’s pretty awesome”. Or, “He’s been lying on the couch for a while, he must be lazy.”

The present tense of lay is laying, which is pretty straight forward. One example is: “She has been laying her coat on my chair every day since she’s moved in.” Or, for special occasions, you can say: “The Golden Goose has been laying golden eggs again!” This works because the golden eggs serve as the direct object in this sentence; it’s a different definition, but the same rule applies.

Okay, here comes the really tricky part.

The past tense of lay is laid. The past participle of lay is also laid. Too easy.

But, the past tense of lie is lay. Not so easy. And, a little ridiculous, if you ask me. To make it a little more difficult, the past participle of lie is lain. Ugh.

(To refresh your memory: the past participle is used to form the perfect tenses–I.e, the verb phrases that have has, have, and had in them.)

Laws of language aside, it is what it is. Your job though is to remember it. I don’t have any funny or stupid-yet-oddly-helpful ways to remember it, so just memorize it. Sorry, guys.

Here’s how to conjugate both lie and lay in the past tense, with examples::


  • Present tense: Lie

I lie in bed at night, thinking about dinosaurs.

  • Past tense: Lay

Yesterday, I lay there thinking about them, too.

  • Past Participle: Lain

And, the night before last, I also had lain in bed thinking about them. I may have a problem.



  • Present Tense: Lay

I lay my coat on this chair, usually.

  • Past Tense: Laid

Earlier, I laid my coat on this chair  But, it’s not there.

  • Past Participle: Laid

Oh, I forgot I had laid my coat on the bed instead. Fail.

Easy? It can be when working with present tense, but it can get confusing when using the past tense. Unfortunately, the only way to learn how to do this properly is by memorizing these rules. But, it gets easier with practice, don’t worry. Soon enough, you’ll be laying and lying all over the place.

Common grammar mistakes– E.g versus I.e.

Common Grammar Mistakes: E.g. versus I.e.

In the world of Internet slang, abbreviations have become the norm. While it’s hard to argue what FWIW or IAWTC mean, E.g and I.e are confused for one another all the time. Of course, these two abbreviations are infinitely older than netspeak as they both have Latin origins. But, despite this and their importance in academic writing, their usage is often misconstrued.Too often are they used interchangeably when they really shouldn’t be.

“So, what do they mean?”

I.e is an abbreviation for the Latin phrase id est, which can be roughly translated to “it is” or “that is”. E.g. is an abbreviation for exempli gratia, or “for example”. You can see where I’m going now.

I.e.  is used to specify or to further clarify a particular. For instance, you would use I.e. to say “I like editors who from New York– I.e., Stefanie Arr” to mean you like only me out of all the editors from New York. (Right?) If that wasn’t so obvious, here’s a better example: “Stefanie Arr is from the big city– I.e., New York.” This is correct because I am from only one big city– New York– and I.e. introduces this clarification.

E.g. is used to give an example or an instance. So, if you say “I like bloggers who write useful advice– E.g., Steve from LSAT Blog“, then you’re saying that you like bloggers who write about useful things, such as Steve, but aren’t limiting your list to just Steve (because I should be included, too.)

A helpful way to remember what each of these abbreviations mean is to use thise easy, if not cheesy, tip: E.g. can be remembered by thinking of it as “egg zample”– like “example” but with a strange, foreign accent. Or, you can take the more mature route and remember that  “E” stands for example.

The way to remember I.e. isn’t so weird a memory trick, but it’s just as useful: just imagine I.e. stands for “in essence”. Or, take the “I” to stand for “in other words”.

“Okay, so what now? How do you use them?”

Well, you can these abbreviations in a number of ways. They are usually used in parenthetical statements, but you can also use them as separate clauses, preceded by a dash (–) or a semicolon (;). You can also use them to introduce either an entirely new sentence. Given what these abbreviations mean, you can use them however you would normally use “in essence”/”in other words” or “for example”.

Easy, right?

Now, here are two last things to note:

  1. Always follow these abbreviations with a comma. So, whether you use them in the middle of a sentence or to start off a new one, always use a comma afterwards, like this “E.g., …”
  2. Don’t italicize them. I italicized them above because I was defining them but, in normal usage, they don’t have to be. This is according to a number of grammatical authorities, including The Chicago Manual of Style.