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Probably one of the most frequent grammar mistakes in the English language is:

The dog sat on it's mat.

Since spelling checkers don't catch it, and it is even logical, since you would correctly write:

The dog sat on Fluffy's mat.

What is the best way to explain to a learner of English how to choose between it's and its?

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6 Answers 6

up vote 33 down vote accepted

This is actually really easy, do you mean "it is" or not?

Frankly native speakers seem to make more mistakes with it than foreign learners.

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+1. Foreign learners simply map it to totally different words in their own native tongue. A German would map "it's" and "its" to "es ist" and "sein", respectively, a Russian to "есть" and "его", a French to "c'est" and "son", etc. In other words, foreign learners learn the difference right from the onset and in their own language, where it is immediately apparent. As a foreign learner myself, I never confuse "it's" with "its", because they are two completely different concepts to me that reside in two completely unrelated areas of my brain. The words are homophones, but the concepts are not. –  RegDwigнt Aug 13 '10 at 8:25
Right. As someone who learned English primarily from reading, I find these mistakes strange: it's as if people were (erroneously) transcribing spoken sound, rather than writing the words themselves. I have to slow down reading when I come across mistakes of this sort (especially "your" and "there"…), and switch to saying the words "aloud" in my mind (called "subvocalization"?) and use the listening-interpretation parts of my brain instead of the reading-interpretation parts. :-) –  ShreevatsaR Aug 14 '10 at 16:29
Just to note that as a native English speaker who is excruciatingly aware of when it is proper to use it’s and its, I do still occasionally mistype or forget an apostrophe with these homophones. Because they have an identical shape phonologically, they become fused in the internal lexicon. All of this is just further evidence that spoken language truly is primary—at least in native speakers. I think it is especially confusing because the concept of possession is usually (with non-pronouns) expressed with an apostrophe. –  nohat Aug 18 '10 at 22:36
+1 Foreign language learners usually get this right. Native speakers learn to speak before they learn the rules and they learn as kids where they associate the sounds with an idea before they attach the metadata of a word "letter picture" to the concept. Similarly, Japanese kids internalize their characters in a completely different way (by rote) as foreign learner do. Children learn by rote well, Adults learn using reason and accumulated knowledge... thus A native Japanese teacher won't have as much success teaching someone their language unless they change the technique. –  Armstrongest Sep 2 '10 at 19:15
@nohat "I think it is especially confusing because the concept of possession is usually (with non-pronouns) expressed with an apostrophe" Why is it different with non-pronouns? Is that worth a question? –  Pureferret Jan 5 '12 at 18:40

Print this out, perhaps.

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+1 funny (and useful) –  Armstrongest Sep 2 '10 at 19:18 is good too ;-) –  kguest Sep 3 '10 at 0:08

The easiest way to remember is that you don't say "he's" or "she's" if you're talking about something someone owns. There are special words for that: "his" and "hers". It follows, then, that there'd be a special word for the genderless "it" too - "its".

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Right. All possessive pronouns have their one words without apostrophes: “his”, “her”, “its”, “their”, “my”, “our”, “your”, “whose” (but “one's”). The corresponding words with apostrophes all mean something else: “he's”, “she's”, “it's”, “they're”, “I'm”, “We're”, "You're”, “Who's”. Many people seem to make mistakes even when writing “they're”, “you're” or “whose”! –  ShreevatsaR Aug 14 '10 at 16:12
This answer and the one by jbelacqua are the only answers to say what pattern it is following, and pointing out that it's not just a weird outlier word that magically doesn't follow the "Bob's object" pattern. –  AlbeyAmakiir Jul 29 '13 at 5:41

If nothing else works, it can be beneficial to point out that none of these related possessive forms has an apostrophe:


If something belongs to it, its form looks just like his and hers .

If it is short for it is, then it's it's .

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You have listed the possessive PRONOUNS not the adjectives. In "The dog sat on its mat, "its" is a possessive determiner (possessive adjective) not a possessive pronoun. For example, Whose mat is this? It's mine / yours / his / hers [It's the dog's] its / ours / theirs. Which would give you It's its. A very ugly construction, but grammatical nevertheless. –  Mari-Lou A Jun 13 at 18:52

Contractions always take an apostrophe. (You can't write cant for cannot.)

Possesives can, but need not. ("Is that her book?" "No, it's Pat's book")

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Shouldn't that be "No, it's Pat's book"? Contractions always take an apostrophe, right? It is Pat's book. –  teylyn Apr 10 '11 at 11:45
It took a year+ for me to notice the comment as I've not been by. But, I hang my head in shame! –  vanden May 7 '11 at 18:34

What is the best way to explain to a learner of English how to choose between it's and its?

• I sat on my mat

• you sat on your mat

• he [my brother] sat on his mat

• she [my sister] sat on her mat

• It [the dog] sat on its mat.

• we [my dog and I] sat on our mats

• you [you and your dog] sat on your mats

• they [he and his dogs] sat on their mats.

Note the total absence of any possessive apostrophe. We do not say * I sat on my's mat. The possessive determiner, its, is precisely what its grammatical term suggests—possessive; hence the genitive or possessive apostrophe is unnecessary.

It's as simple as that.

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