Looking around the net and in almost every forum I visit, I find widespread misuse of the apostrophe and particularly with the use of the word its. Often I see very well written forum posts by people who are obviously well educated in grammar and spelling, but the usage of the apostrophe with the word it remains a universal problem. Somehow it's not being taught properly at school, and to those who are familiar with its correct usage, it looks kind of dumb.
The easiest way to know where to use an apostrophe in this case is to remember that its is the possessive form, as in "the potency of the weed depends on its THC content", and that it's is a contraction of it is (or it has), as in "she says it's good weed". Whenever I see it's I automatically think it is. That's the easiest way to tell if the apostrophe belongs there or not.
From wikipedia:
The easiest way to know where to use an apostrophe in this case is to remember that its is the possessive form, as in "the potency of the weed depends on its THC content", and that it's is a contraction of it is (or it has), as in "she says it's good weed". Whenever I see it's I automatically think it is. That's the easiest way to tell if the apostrophe belongs there or not.
From wikipedia:
For a full explanation of the apostrophe and its usage, see http://en.wikipedia.org/wiki/ApostropheNo apostrophe is used in the following possessive pronouns and adjectives: yours, his, hers, ours, its, theirs, and whose. (Many people wrongly use it's for the possessive of it, but authorities are unanimous that it's can only be a contraction of it is or it has.)