英语语法之现在进行时与一般现在时

现在进行时：动作或事件已经开始进行并且尚未结束。

1. 有些单词一般不用于进行时态

   比如：

   know/like. 一般都说 I know/like , 而不说 I am knowing 或 they are liking

   以下单词一般都不用于现在进行时：

      like want need prefer know realise suppose mean understand believe remember belong fit contain consist seem
   
   

2. think 这个单词得看情况
   当表达的意思为‘认为’‘相信’‘觉得’时，一般不用于进行时，比如：

      I think Mary is Canadian, but I'm not sure, (not I'm thinking)

   当表达的意思为‘考虑’‘思考’时，则有可能用于进行时，比如：

   Nicky is thinking of giving up her job. (= she is considering it)
   

3. See hear smell taste

   一般用于一般现在时，而不用于进行时

   Do you see that man over there? (not Are you seeing)
   This room smells. Let's open a window.
   

   也经常这么用 can + see/hear/smell/taste:

   I can hear a strange noise. Can you hear it?
   

4. look feel
   这两个词既可以用作一般现在时，也可以用于现在进行时

   You look well today, or You're looking well today.
   How do you feel now? or How are you feeling now?
   

   但是在表达‘我经常 (ususlly) 觉得 …’时：

   I usually feel tired in the morning. (not I'm usually feeling)   
   

5. am/is/are being 与 am/is/are

   He’s being = He’s behaving / He’s acting.
   例句：

   I can't understand why he's being so selfish. He isn’t usually like that.(being selfish = behaving selfishly at the moment)
   他 (现在) 怎么变的这么自私了，他以前可不这样。He never thinks about other people. He is very selfish, (not He is being)(= He is selfish generally, not only at the moment)
   他从不考虑别人，非常自私。（一直很自私）