By Marina Pantcheva
It’s is the contraction of it is or it has.
(1) It’s obvious that the experiement is flawed. (= it is)
(2) It’s unnecessary to explain the reasons. (= it is)
(3) I do not like ice cream; it’s too cold. (= it is)
(4) It’s been snowing all week. (= it has)
Avoid using it’s in formal texts; use the full form it is instead.
Its is the possessive form of it.
(4) The chameleon is known for its ability to change appearance.
(5) The puppy chaised its tail.