The apostrophe may be the most abused punctuation mark in the English language. A quick glance at street signs, advertisements, and store marquees will demonstrate that almost no one seems to know how to use this mark properly.
The apostrophe has two, and only two, uses: to show possession and to indicate the omission of letters or numbers. To further illustrate this point, let us examine some of the rules that dictate when apostrophes should be used and where they should be placed in a word.
Common rules
Possessive common nouns are common nouns or pronouns that own other nouns. Apostrophes are used to indicate this possession in the following ways:
If the noun does not end in -s (in most cases this means it is singular), add -'s.
Here are two examples:
The bike's handlebars were bent in the crash.
The boy's sister traveled by bus to meet us.
Contractions
Contractions are shortened versions of words or phrases typically limited to casual speech or writing. Avoid the use of contractions in formal and professional writing. When writing a contraction, remember that an apostrophe marks the place where letters have been omitted. For example:
Don't forget to vote! (Don't is a contraction of do not; the o in not has been omitted.)
I'm so sick of this cold weather. (I'm is a contraction of I am; the a in am has been omitted.)
An apostrophe is also used to indicate the omission of the first two digits of a year or years.
The members of the class of '98 have all gone on to be successful.
The pre-Depression era of the '20s was a time of social change and material excess.
When NOT to use an apostrophe
The most common apostrophe error is the addition of an apostrophe where one is not needed. We have found apostrophes in some pretty strange places. The following are some of the most frequently made errors:
Do not use an apostrophe in the possessive pronouns whose, ours, yours, his, hers, its, or theirs.
Do not use an apostrophe in nouns that are plural but not possessive, such as CDs, 1000s, or 1960s.
Do not use an apostrophe in verbs. Apostrophes sometimes show up in verbs that end in -s, such as marks, sees, or finds.
Some apostrophe mistakes involve the confusion of two words that sound the same but have different meanings.
Confusion of its and it's. Its is a possessive pronoun, while it's is a contraction of it is.
The dog pulled on its leash.
I just realized it's time to go!
Confusion of your and you're. Your is a possessive pronoun, while you're is a contraction of you are.
Don't forget your umbrella.
You're the worst dancer I've ever seen.
Confusion of whose and who's. Whose is a possessive pronoun, while who's is a contraction of who is.
Whose turn is it to take out the trash?
I wonder who's going to play Hamlet.
When in doubt over whether to use an apostrophe, think about the word's (or words') meaning. Does this noun own something? Are two separate words being combined into one contraction?
https://www.scribendi.com/advice/using_apostrophes.en.html
The apostrophe has two, and only two, uses: to show possession and to indicate the omission of letters or numbers. To further illustrate this point, let us examine some of the rules that dictate when apostrophes should be used and where they should be placed in a word.
Common rules
Possessive common nouns are common nouns or pronouns that own other nouns. Apostrophes are used to indicate this possession in the following ways:
If the noun does not end in -s (in most cases this means it is singular), add -'s.
Here are two examples:
The bike's handlebars were bent in the crash.
The boy's sister traveled by bus to meet us.
Contractions
Contractions are shortened versions of words or phrases typically limited to casual speech or writing. Avoid the use of contractions in formal and professional writing. When writing a contraction, remember that an apostrophe marks the place where letters have been omitted. For example:
Don't forget to vote! (Don't is a contraction of do not; the o in not has been omitted.)
I'm so sick of this cold weather. (I'm is a contraction of I am; the a in am has been omitted.)
An apostrophe is also used to indicate the omission of the first two digits of a year or years.
The members of the class of '98 have all gone on to be successful.
The pre-Depression era of the '20s was a time of social change and material excess.
When NOT to use an apostrophe
The most common apostrophe error is the addition of an apostrophe where one is not needed. We have found apostrophes in some pretty strange places. The following are some of the most frequently made errors:
Do not use an apostrophe in the possessive pronouns whose, ours, yours, his, hers, its, or theirs.
Do not use an apostrophe in nouns that are plural but not possessive, such as CDs, 1000s, or 1960s.
Do not use an apostrophe in verbs. Apostrophes sometimes show up in verbs that end in -s, such as marks, sees, or finds.
Some apostrophe mistakes involve the confusion of two words that sound the same but have different meanings.
Confusion of its and it's. Its is a possessive pronoun, while it's is a contraction of it is.
The dog pulled on its leash.
I just realized it's time to go!
Confusion of your and you're. Your is a possessive pronoun, while you're is a contraction of you are.
Don't forget your umbrella.
You're the worst dancer I've ever seen.
Confusion of whose and who's. Whose is a possessive pronoun, while who's is a contraction of who is.
Whose turn is it to take out the trash?
I wonder who's going to play Hamlet.
When in doubt over whether to use an apostrophe, think about the word's (or words') meaning. Does this noun own something? Are two separate words being combined into one contraction?
https://www.scribendi.com/advice/using_apostrophes.en.html
