I learned the pattern that is "had better". it means "would like to" and more polite expression. For example i'd better take a sleep. because i have been tired today to present the paper of AVEC. so I'd better sleep. another sample you'd better see a doctor. The cough is longed in a few days. and it isn't better. last example we'd better stop bothering him. he concentrates the phone named galaxy S3, recieved yesterday. he has looked the phone continuosly. he even doesn't answer my question.! Hm Im gonna to go sleep within 10 minute. ^^