There are many English speakers who have doubts or misconceptions about where to use apostrophes (the character '). In summary, it has two uses.


1. Forming contractions

Apostrophes are used in the shortened forms of phrases that we call contractions, such as can't, don't, couldn't and would've, taking the place of the letters removed. Double contractions such as wouldn't've have two apostrophes, though it should be noted that double contractions are cumbersome and best avoided in all but casual speech.


2. Indicating possession

A noun becomes its possessive form by adding 's - or in some cases, just ' - to the end.

a. General rules:

- Add 's to singular nouns ("the man's car")

- Add ' to plural nouns ("the two girls' dolls")

- Add ' to proper nouns ending in s ("Mr. Douglass' business")

b. Counter rules:

- Add 's to plural nouns that do not end in s ("the children's teacher")

- According to some, add 's to a one-syllable proper noun ending in s ("James's house")



Our subsequent blog posts will examine more advanced aspects of English grammar. For now, we would like to provide the reader with a quick summary of basic points that every English speaker should know (and might know in theory), but many get wrong. English speakers - whether learners or natives - will benefit from keeping this "crib sheet" at hand, so feel free to print it and distribute it.


1. There, their and they're

These words are homophones (that is, they sound the same) but have distinct functions.

a. There: pronoun that indicates location.

"The trees are over there."

b. Their: possessive pronoun that indicates possession by "them".

"Those are their cars."

c. They're: contraction of "they are".

"They're going to the Gold Coast for the holidays."

Synthesis: "They're going to get their shoes wet if they go over there."


2. Its and it's

As with the case above, these words sound the same but work differently.

a. Its: possessive pronoun.

"A leopard cannot change its spots."

b. It's: contraction of "it is".

"It's a lovely day we're having."

Synthesis: "It's a shame that my car has lost its hubcaps."


3. Who's and whose

This is yet another case of homophones that are frequently confused with one another.

a. Who's: contraction of "who is".

"Who's coming to my party on Friday?"

b. Whose: possessive pronoun.

"Whose shoes are these?"

Synthesis: "If you don't put a label on your coat, who's going to know whose it is?"


4. Effect and affect

Generally speaking*, effect is a noun and affect is a verb. The two words, in this context, concern causal relationships

a. "The weather might have had an effect on last night's game."

b. "Prolonged exposure to sunlight can affect your skin."

Synthesis: "I don't like the effect that this decision has had on the public, and I hope it doesn't affect me."


* However, "effect" is used occasionally a verb, meaning "to bring about". "Affect" is a noun when used in reference to mood.

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