The word its, without an apostrophe, is the possessive form of it. The word its is therefore is an exception to the rule that singular possessives are formed with an apostrophe-s (as in “Emma‘s car”).

Headline language, with its many omitted words, complicates syntactic classification.

[The word it’s, with an apostrophe, is not a possessive, but a contraction of the phrase it is.

It’s possible that if global warming continues, malaria could reoccur in Sweden.

NP-Complete problems are intractable, but it’s possible to find a tractable subproblem.]