13 of the most common grammatical errors that show people’s ignorance

2. 'It's' vs. 'Its': Normally, an apostrophe symbolizes possession, as in, "I took the dog's bone." But because apostrophes also replace omitted letters — as in "don't" — the "it's" vs. "its" decision gets complicated.  Use "its" as the possessive pronoun and "it's" for the shortened version of "it is." Example 1: The dog chewed on its bone.  Example 2: It's raining.