A是B。

练习：

1、一般现在时

   一切正常。

   Everything is all right.

   Everything is OK.

2、一般将来时

   我将要成为一名医生。

   I am a doctor.

   I will be a doctor.

3、情态动词

   他不可能在家。

   He is not at home.

   He can not be at home.

练习(主语)：

1、名词     武汉是个大城市。Wuhan is a large city.

2、形容词   他们又饥又渴。They are hungry and thirsty.

3、代词     钱有用，但不是万能。Money is something, but not everything.

4、数词     2020就是20，20。2020 is twenty twenty.

5、副词     大家都到了。Everybody is here.

6、不定式   我的愿望就是出国留学。My wish is to go abroad to study.

7、ing形式  我的愿望就是出国留学。My wish is going abroad to study.

8、过去分词 门是关着的。The door is closed.

9、介词短语 没人在教室里。Nobody is in the classroom.

练习（表语）：

1、名词     伦敦是英国的首都。London is the capital of England.

2、代词     门口有人。Somebody is at the door.

3、数词     5-3=2 Five minus three is two.

4、不定式   见到你很高兴。

   To meet you is nice.(工整)

   It is nice to meet you.（规范）

   Nice to meet you.（简化）

5、ing形式  游泳是我最喜爱的运动。Swimming is my favorite sport.