英语中，什么叫及物动词，什么叫做不及物动词！！！急急急

一　定义：
A 有些动词只是及物动词; 它们不可以单独用，后面必须跟宾语。

{ False: They always want after lunch.
Right: They always want a cup of tea after lunch.
{ False: He is sending now.
Right: He is sending a letter now.

B 有些动词只是不及物动词；它们可以单独用，如果后面想接宾语，动词后面必须加上介词。

{ Right: He is looking around.
False: He is looking me.
Right: He is looking at me.
{ Right: He is listening carefully.
False: He is listening the teacher carefully.
Right: He is listening to the teacher carefully.

C 有些动词既是及物动词，又是不及物动词; 但是有时候词义会改变。

{ The customer is asking loudly.
The customer is asking for you now.
The customer is asking a question now.
{ If you work hard, you will succeed.
If you work hard, you will succeed in passing the exam (same meaning).
If you work hard, you will succeed John as the manager of this company (different meaning).

二　动词使用的建议：

当使用动词时，一定要分清楚这个动词属于哪一类 [动词分类]，然后再根据不同的使用规则使用不同动词。

及物动词指的是后面可以“直接”宾语的动词，也可以按字面理解：可触及东西的动词。不及物之后需要有介词才能接宾语。
比如说I cry.中的cry是不及物动词。I miss you.我想你。中的miss是及物动词。

vt及物动词后面能直接加宾语。如study 是及物动词，可直接加宾语。如：I study English。
VI不及物动词后面不能直接加宾语，需加个介词，然后再加宾语.arrive是不及物动词，它后面要加个介词后再加宾语。如：I arrived in Liaoyang this morning.