通常在句子中有以下的词：now, look, listen.

句子的结构如下：  be      am

                  is   +动词 ing

                  are

如：1. I am listening to the music now.

    2. The students are drawing pictures now.

    3. Listen! She is singing .

    4. Look! Mr Li is riding a bike.

其中，动词的ing形式有如下方法：

   A. 在动词后直接加ing: go-going , wash-washing,fly―flying

   B. 以单个元音+单个辅音+e结尾 ， 去掉e加ing,如 ：drive―driving, ride―riding，make-making, take-taking

   C. 某些单词要双写词尾的字母：swim- swimming      run―running  get--getting

练习：

1．Mr Zheng                 (read) a book now.

2. The rabbits                (jump) now.

3.. Look ! Tom and John                   (swim).

4. My brother                      (make) a kite in his room now.

5. Look! The bus                    (stop).

6. We                    (have) an English class now.

7. Listen! Someone is                   (come).

8. They                      (catch) butterflies now.

9. He                       (do) an experiment now.

10. They                      (collect) stamps now.

11. Look! He                     (dive) now.

12. Tom                 ( watch ) TV in the dining room.

13. The doctors                     (get ) off the bus.

14. Come on. They                   ( leave ) now.

15. It                 (eat) fish now.

16. My father                     (work) in the office now.

17. Where is your mother?She                  (answer) the phone.

18. The teachers                       (run) now.