国产成人v爽在线免播放观看,日韩欧美色,久久99国产精品久久99软件,亚洲综合色网站,国产欧美日韩中文久久,色99在线,亚洲伦理一区二区

學(xué)習(xí)啦>學(xué)習(xí)英語>英語單詞>

be動詞的用法總結(jié)及練習(xí)題(2)

時間: 燕妮639 分享

  be動詞的用法:做助動詞

  助動詞be 有兩個基本用法,一是與謂語動詞一起構(gòu)成各種時態(tài),二是構(gòu)成被動語態(tài)。

  1、“be + 現(xiàn)在分詞組”成各種進(jìn)行式時態(tài)。例如:

  Tony's maid is washing his new car.

  The children are playing in the field.

  Samuel was eating when I came in.

  We have been living here since 1959.

  This time next day they will be sitting in the cinema.

191229