现在进行时：表示现在正在进行的动作
构成： 主语＋be动词＋动词的现在分词＋其它成分
He is reading a book.
The dog is running after a cat.
The boys are swimming across the river.
变疑问句将be动词移到句首
Are we having lunch?
Is he reading a book?
Is the dog running after a cat?
Are the boys swimming across the river?
变否定句在be动词后面加 not
We are not having lunch.
He is not reading a book.
The dog is not running after a cat.
The boys are swimming across the river.
特殊疑问句：what, which, how, where, who, etc.
疑问词＋动词＋主语＋现在分词
What are you doing?
What is she doing?
What is the dog doing?
没有进行时的动词
表示状态，思想，感情和感觉的动词不能表示正在进行的动作
1. 表示感觉，感官的词
see, hear, like, love, want,
2. have, has当”拥有”讲时没有进行时
