Is he studying? ----Yes, he is. / No, he isn’t.
4.特殊疑问句：疑问词+一般疑问句
例：What are you doing?
What is he doing?
Who is singing?
四、 动词变化：
1.一般情况下直接加ing：
think---thinking sleep---sleeping study---studying
speak---speaking say---saying
2.以不发音的字母e结尾的单词，去掉字母e,再加ing
wake---waking make---making come---coming
take---taking leave---leaving have---having
dance----dancing ride----riding write---writing
3. 以重读闭音节结尾，呈现辅，元，辅结构的动词，先双写末尾的辅音字母，再加ing
stop---stopping sit---sitting run---running
4.以ie结尾的动词，把ie改为y，再加ing
lie---lying
五、没有进行时的动词：
1.表示感觉的感官动词：feel, hear, smell, see
2.表示思想状态的：believe, forget, know, remember
3.表示喜怒憎恶，人物内心感觉，态度情感等描述性动词：like, hate, love, prefer
4.表示要求，愿望：hope, want, wish, wonder
5.表示所属关系或存在状态动词：belong to, have appear, fit, matter, seem