Apostrophes (2): ITS and IT’S

Many British people make the mistake between ITS (no apostrophe) and IT’S (with an apostrophe).  So…

1. “It’s hot today.” = IT IS HOT TODAY = APOSTROPHE FOR LEAVING OUT A LETTER

2. “I have a new car. Its top speed is 120 mph.” = POSSESSIVE = THE TOP SPEED OF IT. = NO APOSTROPHE FOR POSSESSION

A great practice page here from better-english.com.