1. To make a statement on Twitter is to tweet, so to repeat a statement on Twitter is to RE-tweet, right? If you see a comment from someone you’re following, you can retweet what they said to all your followers. That way, your followers who aren’t following the person who made the pithy comment can have the chance to see it, too. (Twitter is all about sharing!)
2. You can retweet (RT) in two ways. You accomplish the classic RT when you copy and paste the original tweet in the What’s Happening text box; then type the letters RT before @ and the username of the original tweeter.
3. The second (new improved) way to retweet is to find a tweet in your tweet stream (just as you did in the @ reply). Hover your mouse pointer over the right side of the tweet and the word Retweet will show up next to a little recycling symbol.