【答案解析】a. He will be a teacher. 表示将要发生的动作行为，动词用原形。
b. I am a teache. 现在时，单数第一人称。
c. She is a painter. 现在时，单数第三人称。
d. Theyr are workers. 现在时，主语是复数。
e. He was a teachers. 过去时，主语是单数。
f. We were workers. 过去时，主语是复数。
g. I have been a teachers for twenty years. 现在完成时，表示从过去延续到现在的行为状态。
h. The newspaper is being read. 被动语态，进行时。