以下是四级常见的一些句型结构：
1.陈述句：S + 主语 + 谓语 + 宾语 (如：I like apples.)
2.疑问句：W + 主语 + 动词原形 + 宾语从句 (如：Do you eat apples?')
3.祈使句：Example: Please eat more fruits and vegetables.(如：Please do your homework.)
4.陈述句的被动语态：(be/se) done by ∗∗./sth./the action of ∗∗./sth.be done in the future/have been done in the past/will be done in the future) (如：The cake is been baked by me.)
5.现在进行时：(be/se) doing sth./there is/has been/has been doing sth.(如：I am watching TV now.)
6.过去进行时：(be/se) did sth.(如：I did my homework yesterday.)
7.将来进行时：(be/se) will do sth.(如：I will go to the store tomorrow.)
8.现在完成时：(have/has) done sth.(如：I have finished my homework today.)
9.过去完成时：(have/has) done sth.(如：He has finished his work before he went home.")
