Digital SAT Writing: Apostrophes and Possessives

Mastering apostrophe rules is a non-negotiable skill for the Digital SAT Writing section. While they seem like minor punctuation marks, their misuse is a common and easily tested error. The SAT expects you to distinguish between possessive forms and contractions, handle tricky singular and plural nouns, and apply these rules flawlessly within the context of editing passages. Your ability to spot and correct these errors directly impacts your score.

The Apostrophe’s Two Distinct Jobs

The apostrophe serves only two primary functions: to show possession (ownership or belonging) and to form contractions (shortened combinations of words). The most frequent SAT errors arise from confusing these two uses or applying the rules incorrectly.

Possession indicates that something belongs to someone or something. For example, in "the student's notebook," the apostrophe + "s" shows the notebook belongs to the student. Contractions, on the other hand, combine two words by replacing omitted letters with an apostrophe. "It's" is a contraction for "it is," and "they're" contracts "they are." The SAT will often place the incorrect form in a passage to see if you notice. A reliable strategy is to mentally expand any word with an apostrophe. If you can say "it is" or "they are," you need the contraction. If you’re indicating ownership, you need the possessive.

Forming Singular and Plural Possessives Correctly

The rules change slightly depending on whether the noun owning something is singular or plural. Consistency is key.

For singular nouns (one person, place, or thing), you almost always add 's to form the possessive, regardless of the noun’s ending letter.

• The cat's paws. (One cat)
• The boss's office. (One boss)
• Chris's textbook. (One person named Chris)

For regular plural nouns that end in "s," you only add an apostrophe after the existing "s."

• The cats' paws. (More than one cat)
• The bosses' meeting. (More than one boss)
• The students' lounge. (Many students)

This distinction is frequently tested. You must identify whether the "owner" in the sentence is singular or plural to select the correct form. A question might present you with a sentence where "the teachers lounge" is underlined, and you must choose between "teacher's," "teachers'," or "teachers." Knowing the lounge belongs to multiple teachers tells you the correct answer is the plural possessive: teachers'.

Handling Irregular Plurals and Joint Possession

Some nouns have irregular plural forms that do not end in "s" (e.g., men, women, children, people, mice). For these irregular plural nouns, you treat them like singular nouns and add 's to form the possessive.

• The children's playground.
• The women's history month.
• The people's choice.

Another scenario involves joint possession, which indicates two or more people own something together. When two nouns share possession, you add the 's only to the final noun listed.

• Kim and Alex's project. (They worked on the same project together.)
• Contrast this with individual possession: Kim's and Alex's projects are due. (They each have their own separate projects.)

The SAT may test your attention to detail by placing a sentence where joint possession is implied but the apostrophe is incorrectly placed on the first noun only.

Navigating the Trickiest Contractions: Its/It's and Their/They're/There

This family of words represents the most common apostrophe-related traps on the SAT. You must be able to differentiate them instantly.

Its vs. It's: Its (without an apostrophe) is the possessive form, meaning "belonging to it." It's (with an apostrophe) is only ever a contraction for "it is" or "it has." The foolproof test is to substitute "it is" into the sentence. If it fits, use it's. If you’re showing possession, use its.

• The company revised its policy. (The policy belongs to it.)
• It's clear that the policy is effective. (It is clear.)

Their vs. They're vs. There: This trio expands the challenge. Their is a possessive pronoun (belonging to them). They're is a contraction for "they are." There indicates a place or is used in impersonal constructions ("There are...").

• The students left their books in there, and now they're late for class.
• SAT trick: A sentence might read, "The team is proud of they're dedication." The word "dedication" is owned by the team, so the possessive their is required, not the contraction they're.

Common Pitfalls

1. Using an apostrophe to form a simple plural. This is never correct. Nouns become plural by adding "s" or "es," not an apostrophe + s.

• Incorrect: The student's (meaning multiple students) were studying.
• Correct: The students were studying.

1. Misplacing the apostrophe in plural possessives. The most common error is adding 's to a regular plural noun that already ends in "s."

• Incorrect: The girl's locker room (implies one girl).
• Correct for multiple girls: The girls' locker room.

1. Confusing its with it's. Because we use 's for most possessive nouns (dog's, city's), our instinct is to do the same for pronouns. Remember: possessive pronouns (its, yours, theirs, ours) never use an apostrophe.

• Incorrect: The tree shed it's leaves.
• Correct: The tree shed its leaves.

1. Assuming a word ending in "s" is plural. Words like "physics," "mathematics," or "United States" are singular in meaning. Their possessives follow the singular rule: add 's.

• Correct: Physics's fundamental laws; the United States's policy.

Summary

• An apostrophe has only two uses: to show possession (ownership) or to form a contraction (like don't for "do not").
• For singular nouns, add 's to form the possessive. For regular plural nouns ending in "s," add only an apostrophe.
• Irregular plural nouns (e.g., children) form the possessive by adding 's.
• Its is possessive ("belonging to it"); it's is only ever a contraction for "it is" or "it has."
• Their shows possession ("belonging to them"); they're is a contraction for "they are."
• Never use an apostrophe to make a word plural. The plural of "book" is "books," not "book's."