had better最好,各个人称都用它
had better do sth.最好做某事,如； You'd better put on your coat.It's raining outside.你最好穿上雨衣,外面在下雨
had better no do 最好别做某时：如：You'd better not play computer for a long time because it's bad for your health.你最好别玩太长时间的电脑,因为对你身体不好.