用适当的非谓语动词形式填空ioftenhearhim(sing).iheardhim(sing).iheardhin(sing)justnow.并说明为什么.要讲解的好、

Question

用适当的非谓语动词形式填空
i often hear him ______(sing).
i heard him _____(sing).
i heard hin _____(sing)just now.
并说明为什么.
要讲解的好、

Answer 1

先说明hear后面的动词只有两种形态：一种是加动词原形,另一种是加动词的现在分词（也就是ing形式）
i often hear him ___sing___(sing).
经常听到就是说这件事经常发生,所以用动词原形.
i heard him __singing___(sing).
听到了他唱歌,没有说明是经常发生,用ing形式.
i heard him ___sing__(sing)just now.
受句式影响不能用过去式,记住就可以了.
能理解吗?