【简明语法】21.9 had better表示"最好"

　　had¹ better 相当于一个助动词，它只有一种形式，它后面要跟动词原形。
　　had better do sth
　　had better not do sth
　　It is pretty cold. You'd better put on my coat.
　　She'd better not play with the dog.


　　had better have done sth表示与事实相反的结果，意为"本来最好"。
　　You had better have come earlier.

1 had   

vbl.have的过去式和过去分词；conj.有

参考例句：

• I just had a good idea!我有个好主意！
• The boy had a small branch of a tree in his hand.这个男孩手上拿一条小树枝。