主谓一致
1.语法一致原则
①以单数名词或代词动词不定式短语，动名词短语或从句作主语时，谓语动词一般用单数形式；主语为复数时，谓语动词用复数形式。
His father is working on the farm.
To study English well is not easy.
Reading in the sun is bad for your eyes.
What he said is very important for us all.
由what引导的主语从句，后面的谓语动词多数情况用单数形式，但若表语是复数或what从句是一个带有复数意义的并列结构时，主句的谓语动词用复数形式。
what I bought were three English books.
What I say and do is （are） helpful for you.
②由连接词and或both…and连接起来的主语后面，要用复数形式的谓语动词。但若所连接的两个词是指同一个人或物时，它后面的谓语就用单数形式。由and 连接的并列单数主语前如果分别有no， each， every 或more than a （an）/one，many a （an） 修饰时，其谓语动词要用单数形式。either， neither， each， every 或no+单数名词和由some， any no， every构成的复合不定代词，都作单数看待。
The writer and artist has come.
Every student and every teach is in the classroom.
Many a boy and many a girl likes it.
No boy and no girl likes it.
Each of us has a new book. Is everyone here today？
Somebody is speaking in class. Everything around us is matter
若none of 后面的名词是不可数名词，它的谓语动词就要用单数。若它后面的名词是复数，它的谓语动词用单数或复数都可以。
None of the sugar was left.
None of us has （have） been to America.
