Mr.Jones and his wife (are) looking at them 和Sometimes he and his wife watch televsion.区别:Mr.Jones and his wife are looking at them 和Sometimes he and his wife watch televsion区别:为什么前面一句看要用系动词are,后一句却不用,但是我是一个人在家自学,所以对我来说理解起来比较困难!

问题描述:

Mr.Jones and his wife (are) looking at them 和Sometimes he and his wife watch televsion.区别:
Mr.Jones and his wife are looking at them 和Sometimes he and his wife watch televsion区别:为什么前面一句看要用系动词are,后一句却不用,但是我是一个人在家自学,所以对我来说理解起来比较困难!

前一句的时态是现在进行时,其结构为:be+doing sth
后一句的时态是一般现在时,sometimes就可以体现,当主语是第三人称单数时,谓语动词要相应的使用三单形式,如果是其他人称,谓语动词用原形。

这涉及到英语的时态问题。第一句侧重指正在看,强调动作。后一句只是简单陈述一件事情。
即,前一句是现在进行时。后一句是一般现在时。你可以看看英语时态方面的书

前面一句表示的是现在进行时,用 be doing something
后面一句表达的是一般情况,用动词原形

第一句中are looking at是现在进行时的用法;
第二句中watch是一般现在是的用法。
时态不同哦。