动词的分类 
根据其在句中的功能，动词可分为行为动词、系动词、助动词和情态动词四类，有些动词是兼类词。如： 
We have lunch at 12. 我们12点吃午饭。(have是行为动词) 
We have been to New York. 我们去过纽约。(have是助动词) 
I am hungry. 我饿了。(am是连系动词) 
She was beaten on the way home. (was是助动词) 
You needn’t have waited for me. 你本来不必等我。(need是情态动词) 
The door needs painting. 这个门需要油漆了。(needs及物动词)
行为动词的分类
及物动词与不及物动词
根据后面是否带宾语，行为动词又可分为及物动词和不及物动词，及物动词(vt. ) 后面要跟宾语，不及物动词(vi. ) 不跟宾语。
如：They study hard. (study后没有宾语，是不及物动词) I know them well. (know后有宾语them，是及物动词)
注：有的动词既可作及物动词，也可用作不及物动词. 如：
She sings very well. （sing是不及物动词）
She sang an English song just now. (sing是及物动词)
延续性动词和非延续性动词
根据动作是否延续，行为动词又分为延续性动词和非延续性动词。如: rain, live, work, learn是延续性动词，go, come, leave, start, 是非延续性动词。
注：非延续性动词在肯定句中通常不与表示时间段连用的for短语连用。
如：[译]他离开这里三天了。 [误]He has left here for three days.
[正]He has been away from here for three days. [正]He left here three days ago.