American vs British English: What's Different?

In this video, Alisha answers 5 questions. - What is the biggest difference between American and British English? - When we do we use for/from/at? What is the difference between American and British English? - My question is: What's the correct form to use "already", "still" and "yeat"? - What's that mean? or What does that mean? Which one is correctly? - What is the difference sanitize and sterilize? I put my blanket to the top to dry and clean out of bacteria, what is best thing?