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Skidmore College
The Skidmore Guide to Writing

The Skidiot's Guide to Grammar


In this section, you'll find a grammar brush-up to help you avoid some common sentence errors.


What is a clause? There are two types of clauses: independent clauses and dependent clauses.

An independent clause can stand alone as a complete sentence.

Example: The Skidmore student passed all her final exams.

A dependent clause cannot stand alone as a complete sentence because it "depends" on more information to finish the thought.

Example: Since the Skidmore student failed all her final exams.

The above clause is a dependent clause because it is not a complete thought. It has a subject and a verb, but the word "since" indicates that there is some information missing.

Combining clauses

When you write sentences, you have some choices as to how to use independent and dependent clauses. Just remember these rules:

  • You can combine two independent clauses when you use correct punctuation.
  • You can combine a dependent clause and an independent clause.
  • You simply can use an independent clause as a full sentence.
  • You cannot join two dependent clauses to make a full sentence.
  • You cannot let a dependent clause stand alone as a sentence.

Example 1: Combining clauses with a coordinating conjunction

When you combine two independent clauses, you need a connecting word along with the comma. The connecting words are called coordinating conjunctions: for, and, nor, but, or, yet, so.

Here are two independent clauses, each a full sentence: Kate was the best player on the team. She was the smartest girl in her graduating class.

To combine these independent clauses, we use a coordinating conjunction: Kate was the best player on the team, and she was the smartest girl in her graduating class.

Notice we used the coordinating conjunction "and" along with a comma. Also notice that the comma goes before the coordinating conjunction. (A common mistake is to put the comma after the coordinating conjunction.)

Example 2: Combining clauses with a subordinating conjunction

When you combine a dependent clause and an independent clause, you need a subordinating conjunction. Here are some subordinating conjunctions: since, because, although, after, as, as though, before, if, once, since, though, unless, until, when, whether, while.

Unlike coordinating conjunctions, which join two independent clauses and are placed after the comma that separates the two clauses, subordinating conjunctions are placed at the beginning of a clause - which means they can appear at the very beginning of the sentence.

Example: When the Skidmore student's parents came to visit, they were appalled at the mess in his dorm room.

Notice that we've used the subordinating conjunction "when" at the beginning of the sentence. If we discarded the subordinating conjunction, we could make this into two independent clauses: The Skidmore student's parents came to visit. They were appalled at the mess in his dorm room.

Here's another example: Because Alex wore his Superman costume to school, everyone laughed at him.

Notice that "Because Alex wore his superman costume to school" is a dependent clause that begins with a subordinating conjunction, and "everyone laughed at him" is an independent clause. "Everyone laughed at him" could be a complete sentence, but "Because Alex wore his Superman costume to school" cannot stand as its own sentence. When a dependent clause is followed by an independent clause, separate them with a comma.

Example 3: Combining clauses with a semicolon

You can join two independent clauses by placing a semicolon between them. Make sure the clauses are closely related in meaning. The lecturer who spoke on Wednesday inspired controversy; the students asked for a study group to consider his topic further.

In the section on punctuation, you'll find more information about using semicolons.


A fragment is an incomplete sentence; it lacks something to complete the thought. The most obvious fragments are missing either a subject or a main verb.

The following is a fragment: Hiding a rabid gorilla in Becky's dorm room.

This has a verb, but no subject. It leaves you wondering, "who was hiding a rabid gorilla in Becky's dorm room?" We need more information. We could make this a complete sentence by saying, "Jennifer was hiding a rabid gorilla in Becky's dorm room."

Another fragment: The Skidmore student.

A complete sentence needs a "who" and a "what." The sentence above has a subject ("who") but no verb ("what"). So, the sentence leaves you wondering "what about the Skidmore student?" As a complete sentence, this might read, "The Skidmore student fell asleep in class."

Comma splices

A comma splice occurs when a comma is used incorrectly in place of a semicolon or without a coordinating conjunction to join two independent clauses.

Here's an example of a comma splice: The Skidmore student tried to stay awake all night, she fell asleep before sunrise.

The problem here is that a comma is being used to join two independent clauses, but we've forgotten also to use a coordinating conjunction. Here's how the sentence would look revised correctly: The Skidmore student tried to stay awake all night, but she fell asleep before sunrise.

Notice that we added the coordinating conjunction "but" after the comma.


Agreement means consistency. That is, if a noun is singular, it takes a singular verb form or pronoun; if a noun is plural, it takes a plural verb form or pronoun.

Noun-verb agreement

Here are some examples of noun-verb agreement.

  • I am at home. ("am" agrees with the subject, "I")
  • She is at home. ("is" agrees with the subject, "she")
  • The girls are at home. ("are" agrees with the subject, "the girls")

Pronoun-noun agreement

Pronouns take the place of nouns. If a pronoun replaces a subject, use these pronouns: I, she, he, it, they, we.

  • My brother and I will go to Florida in May.

If pronouns come after a preposition in a sentence, use these pronouns: me, her, him, it, them, us.

  • Send a reply to Sally and me.
  • The book belongs to him.

Here is a typical pronoun error: Me and her went to the movies.

"Me" and "her" cannot be used as the subject of a sentence. Therefore, the correct sentence is: She and I went to the movies.

Here's another example of the same type of error: The pizza was divided between my roommate and I.

Since the pronoun comes after the preposition "between," the sentence should read: The pizza was divided between my roommate and me.

A singular pronoun should replace a singular noun; a plural pronoun should replace a plural noun. Here, for example, is a very common pronoun mistake with a few possible revisions: Any Skidmore student can decorate their dorm room with posters.

This is grammatically incorrect because "Any Skidmore student" refers to a single student, and the pronoun "their" is a plural possessive pronoun. (In the same way, "each Skidmore student" refers to a single student, not to everyone.) There are two ways to revise such a sentence:

Any Skidmore student can decorate his or her dorm room with posters.
Skidmore students can decorate their rooms with posters.
If you want to avoid gender bias in choosing pronouns, changing a noun to a plural can help solve the problem. In general, overusing "his or her" construction makes writing awkward.

Parallel construction

Parallel construction means that words or phrases are written in the same form. If one phrase in a list begins with "of," then other phrases should, too. If one phrase uses the verb form ending in "ing," then other phrases should, too. Here is an example of mismatched sentence parts: I like skiing, ice skating, and to hike.

Here we have two "ing" verb forms and one infinitive ("to hike"). By using matched parts, we can improve the parallelism:

  • I like to ski, ice skate, and hike.


  • I like skiing, ice skating, and hiking.


A modifier is a word or phrase that describes or explains another word in the sentence.

I only went to school on Friday.

In this sentence, the word "only" is a modifier. Right now, it modifies the word "went" because it is closest to that word. The sentence could mean that on Friday the writer did nothing else but go to school. But suppose the writer wants us to know that last week she went to school only on one day. In that case, the sentence should read:

I went to school only on Friday.

You need to be careful about where you place modifiers because a misplaced modifier can cause grammatical problems.

Example:The Skidmore student was told that she had been expelled from school by the professor.

Was the Skidmore student told by the professor that she had been expelled? Or was she told by someone else that the professor had expelled her? Who expelled her and who told her the news? Are they the same person? The sentence ends up being too confusing. Here is the same sentence revised:

The professor told the Skidmore student that she had been expelled from school.

Now it's clear that the professor is the person who told the Skidmore student the unfortunate news.

Dangling modifiers

Having completed the assignment, the television was turned on.

The problem here is that this sentence says the television completed the assignment. We can guess, since televisions don't generally do that sort of thing, that the person who turned on the television is missing from the sentence. We can revise the sentence by adding a subject for the first part of the sentence to modify: Having completed the assignment, Jonas turned on the television.

Notice that the introductory phrase "having completed the assignment" refers to Jonas.

Who or whom?

The easiest way to remember which of these to use Is to remember that "who" is a replacement for subject pronouns (he, she, they) and "whom" is a replacement for the object pronouns (him, her, them).

  • Who is taking Katie to the prom? He is taking Katie to the prom.
  • Whom are you voting for in next week's election? I'm voting for him.


In this section, you'll find information about how to use commas, semicolons, colons, hyphens, and apostrophes.

Commas (, )

Commas tell the reader to pause, but the pause needs to be justified by a grammatical reason. Commas should never be placed in a sentence arbitrarily. However, if you don't know the rules regarding commas, you will either overuse them or neglect to place them where they should be used. Commas are used

1) To join two clauses:

When Joe arrived at school, he realized that he'd forgotten to wear pants.

In this sentence, the comma joins a dependent and independent clause.

Joe arrived at school half-dressed, and he blushed from head to toe.

In this sentence, the comma and a conjunction join two independent clauses.

2) After an introductory word:

However, Alex's dorm room was too small for his pet mongoose.

3) Around nonessential clauses:

The philosophy professor, who drove a hot-pink Rolls-Royce, taught several classes at Skidmore.

A clause is not essential when it is not needed to define another word in the sentence. It's interesting to know that the professor drives a Rolls-Royce, but by placing commas around this information, the writer is telling us that this information is not needed to define which philosophy professor is the subject of the sentence. Suppose, though, there were two philosophy professors who might be the subject. Then the reader needs to know that the one who drove the Rolls taught several classes at Skidmore. In that case, you would omit the commas and write

The philosophy professor who drove a hot-pink Rolls-Royce taught several classes at Skidmore.

You as the writer, then, decide whether or not a clause is essential.

4) In a series or a list:

Caroline's favorite foods include grapes, watermelons, tomatoes, and pineapples.

Note: Place a comma after the next-to-last item in the list, in this case "tomatoes."

5) To separate two adjectives that describe a noun (only use commas here if you can switch the order of the words and not affect the meaning of the sentence):

  • Skidmore is a co-ed, liberal arts college.
  • or
  • Skidmore is a liberal arts, co-ed college.

Semicolons (;)

When you first grasp the rules of how to use semicolons, you'll be tempted to overuse them. However, the semicolon won't be necessary most of the time. Nonetheless, here are the rules:

A semicolon can be used

1) To join two independent clauses that make sense when combined.

Kate liked to take long walks on the beach; Alex preferred building sandcastles.

2) To join two independent clauses along with a joining word.

Kate liked to take long walks on the beach; however, Alex preferred building sandcastles.

Note: Since "however" is NOT a conjunction, it cannot be used only with a comma to join two independent clauses.

Keep in mind, a period could be used in either of the above examples. If you choose to use semicolons to join clauses, you're really making a stylistic choice rather than a grammatical one. And don't forget, you shouldn't capitalize the first letter of the word that follows a semicolon unless it is a proper name.

3) To separate items in a list when one or more of the items contains a comma.

Tracy brought her pet hamster, Pickles; her three hundred CDs; and her antique, mahogany lounge chair to her dorm room.

Since two items in this list contain commas, using commas as a separator will cause confusion for the reader.

Note: Do not use a semicolon to join a phrase or incomplete sentence to an independent clause.

Wrong: Alex liked to build sandcastles on the beach; which was how he spent last summer.
Correct: Alex liked to build sandcastles on the beach, which was how he spent last summer.

Apostrophes (')

Apostrophes have two uses: to indicate a contraction and to show possession.

In contractions, use an apostrophe in place of the letter or letters that are missing.

  • Do not = don't
  • He will = he'll

To show possession, use an apostrophe and "s" after a singular noun.

  • Caroline's pet mongoose ran loose all over campus.
  • The teenager's car had leopard upholstery.

To show possession when a plural noun ends in an "s," put the apostrophe after the "s."

  • The dogs' collars matched their leashes.

Don't use apostrophes to make a family name (or any other word) plural:

  • The Goldsteins arrived late to their family-therapy session and found the Briggses had been given their time slot.

However, do use an apostrophe to show possession for plural family names:

The Joneses' appointment had to be rescheduled.

To make plurals of letters, numbers, and abbreviations, some writers add an "s' and some add an apostrophe and "s." Be consistent.

  • CODs, IOUs, the early 1920s
  • Ns, Bs, Ph.D.s, 1930's

Here are some exceptions that often lead to errors:

Don't confuse "whose" and "who's"

  • "who's" is a contraction for "who is"
  • Who's missing his underwear?
  • "whose" refers to possession
  • Whose underwear is this?

Don't confuse "it's" and "its"

  • "It's" is a contraction for "it is".
  • It's always a good idea to wear matching socks.
  • "Its" is the possessive form of "It."
  • Although the peach was gigantic, its pit was rather small.

Hint #1: Whenever you see an apostrophe with "its," read the apostrophe as an "i." So, if the sentence reads, "Although the peach was gigantic, it's pit was rather small," you could try reading "it's" as "t is" and see if the sentence makes sense. It doesn't, so you know that the apostrophe is incorrect.

Hint #2: Learn the difference between "It's" and "its." This error drives professors crazy.

A plural noun that does not end in "s" needs an apostrophe and "s" to form the possessive.

  • The children's toys covered every surface of the living room.
  • The recent campaign focused on women's issues.

Colons (: )

Use a colon at the end of an independent clause to introduce a list, an explanation of the clause, or an example:

There are many interesting things in Billy's closet: old shoes, fluffy pompoms, and hundreds of baseball cards.

Don't use a colon after a verb or a phrase like "such as" or "consisting of" or after a form of "to be" (am, is, are, was, were).

Hyphens (-)

Use a hyphen to indicate compound words:

  • Mother-in-law

Use a hyphen to join two word units:

  • Long-standing

Use a hyphen to avoid doubling vowels and tripling consonants:

  • Anti-intellectual instead of antiintellectual

Use a hyphen between words that are spelled alike but have different meanings:

  • Re-creation does not mean the same thing as recreation.

Use a hyphen to form a compound adjective preceding a noun:

  • Spike Lee is a well-known film director.

Do not use a hyphen to form a compound word after a linking verb.

  • Film director Spike Lee is well known.

Punctuation with quotations

First, it's important to know when to use a quotation. Don't quote simply because you can't think of a better way to phrase something. Quotations should support your thesis, and they should come after you've already used your own words to explain something - not instead of your own words. And, when you do quote something, explain where the quotation is coming from; many students tend simply to throw in the quotation after their idea is stated. You have to "set up" a quotation. (You'll find more about quotations in Part Two of this guide.)

Remember: Quotations don't speak for themselves. You need to tell the reader what the quotation means and how it relates to your own ideas.

Here's an example of a properly used quotation:

Many students at Skidmore have been concerned that they won't be able to find jobs after they graduate. One student even commented, "I'm worried I'll have to work at McDonald's for the rest of my life!"

Notice how the writer explains the concerns of the students before quoting. And notice how the quotation is set up by a lead-in phrase.

Here's an example of the same information with a misuse of quotation:

Many students at Skidmore have been concerned that they will "have to work at McDonald's for the rest of" their lives.

In the sentence above, the quotation is not introduced properly; the reader can have no idea who is being quoted. Is it a student? A parent? Someone from the Career Services office? Remember, your professors are looking for evidence that you can express your ideas and then support them with quotations, not simply use a quotation to replace your own words.


The basic rule is this: commas and periods go inside quotation marks; semicolons and colons go outside of quotation marks. (If you are reading a source printed in the United Kingdom or Canada, you'll see commas and periods outside of quotation marks. Nevertheless, you need to learn and to use American conventions.)

If the quotation you are using in the sentence is a question, the question mark goes before the second quotation mark:

  • During the meeting Matt asked, "When can we leave?"

If the sentence itself in a question, the question mark goes after the second quotation mark.

  • What do you think Matt meant when he said, "I want to leave"?

If you intend to cite the quotation you are using, then the period will go after the parenthesis:

  • "To be or not to be" (Hamlet V165).

If you are not citing the quotation, you must put the period before the second quotation mark:

  • Gabby told Becky, "Please don't eat all the muffins."

Capitalizing with quotations

Do not capitalize quoted speech when the first quoted word does not begin the sentence you are quoting.

  • Lisa was talking about how much she liked LS, "especially when Professor Solomon is giving the lecture."

When the quotation follows the word "that," do not use a comma, and do not capitalize the first letter of the quotation.

  • Professor Smith told the class that "knowing how to do research is a valuable skill."