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?

  • You are writing something that is wrong stating it is wrong in the comments, but still... would it be possible to write it crossed out?
    – ntg
    Commented Oct 12, 2020 at 10:49

8 Answers 8


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.

  • 23
    +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
    Commented Aug 13, 2010 at 8:25
  • 14
    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. :-) Commented Aug 14, 2010 at 16:29
  • 14
    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
    Commented Aug 18, 2010 at 22:36
  • 7
    +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.
    – OneProton
    Commented Sep 2, 2010 at 19:15
  • 1
    Without the other answers, it looks like this one is saying that the word "its" simply doesn't follow the same pattern as words like "Bob's", and therefore is a weird outlier word that doesn't follow any pattern. In fact, it does follow a pattern; the pattern of "his", "hers", etc. It should probably mention that to be a more complete answer. Commented Jul 29, 2013 at 5:49

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".

  • 3
    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”! Commented Aug 14, 2010 at 16:12
  • 1
    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. Commented Jul 29, 2013 at 5:41

Print this out, perhaps.



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 .

  • 2
    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
    Commented Jun 13, 2015 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")

  • 1
    Shouldn't that be "No, it's Pat's book"? Contractions always take an apostrophe, right? It is Pat's book.
    – teylyn
    Commented Apr 10, 2011 at 11:45
  • 2
    It took a year+ for me to notice the comment as I've not been by. But, I hang my head in shame!
    – vanden
    Commented May 7, 2011 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.


Lynne Truss in her book Eats, Shoots & Leaves: The Zero Tolerance Approach to Punctuation explains it in a rather straightforward manner:

The rule is: the word 'it's' (with apostrophe) stands for 'it is' or 'it has'. If the word does not stand for 'it is' or 'it has' then what you require is 'its'.


It needs to be understood that there was much disagreement about this up until maybe 60 years ago, when the "authorities" finally agreed that the possessive of "it" should be "its", to avoid confusion with the contraction "it's", meaning "it is" or "it has".

Like any such change in the "rules" of English, it's taken decades to take hold. And, I'll have to admit, when keyboarding its fairly easy to get it wrong.

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