下面几句英文错在哪里?

问题描述:

下面几句英文错在哪里?
1)名词的单复数前后不统一
Exams are necessary because it helps improve ourselves in many ways.
2)时态、语态、主谓不一致
Having family teachers are very common among students.
3)副词位置或选用不当
We also can do something for our parents to show our thanks .
4)表达随意,中国式英语比比皆是
There are a large number of tourists visit Shanghai every year.

it helps 改为 they help
are改为 is,  此句主语是 Having family teachers,别让teachers影响对主语的判断.
also放到can的前面,当句子中有情态动词时,修饰谓语动词的副词要放在 谓语前面.
visit 前面加个that,同一个句子中不可以出现两个谓语动词,加that后,变成是that引导的定语从句,修饰tourists.