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。如：His father is working on the farm./ To study English well is not easy./ What he said is very important for us all./ The children were in the classroom two hours ago./ Reading in the sun is bad for your eyes.
注意：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。如：What I bought were three English books./ What I say and do is (are) helpful to you.
2.由连接词and或both …… and连接起来的合成主语后面，要用复数形式的谓语动词。如：Lucy and Lily are twins./ She and I are classmates./ The boy and the girl were surprised when they heard the news./ Both she and he are Young Pioneers.
注意：(1)若and所连接的两个词是指同一个人或物时，它后面的谓语动词就应用单数形式。如：The writer and artist has come.(2)由and连接的并列单数主语前如果分别有no,each,every more than a (an) ,many a (an)修饰时，其谓语动词要用单数形式。如：Every student and every teacher was in the room./ No boy and no girl likes it.
3.主语为单数名词或代词，尽管后面跟有with,together with,except,but,like,as well as,rather than,more than,no less than,besides,including等引起的短语，谓语动词仍用单数形式;若主语为复数，谓语用复数形式。如：Mr.Green,together with his wife and children,has come to China./ Nobody but Jim and Mike was on the playground./ She,like you and Tom,is very tall.
4.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。如：Each of us has a new book./ Everything around us is matter.
注意：(1)在口语中当either或neither后跟有“of+复数名词(或代词)”作主语时，其谓语动词也可用复数。如：Neither of the texts is (are) interesting.(2)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。如：None of us has (have) been to America.
5.在定语从句时，关系代词that,who,which等作主语时，其谓语动词的数应与句中先行词的数一致。如：He is one of my friends who are working hard./ He is the only one of my friends who is working hard.
6.如果集体名词指的是整个集体，它的谓语动词用单数;如果它指集体的成员，其谓语动词就用复数形式。这些词有family,class,crowd,committee,population,audience等。如：Class Four is on the third floor./ Class Four are unable to agree upon a monitor.
注意：people,police,cattle等名词一般都用作复数。如：The police are looking for the lost child.
7.由“a lot of,lots of,plenty of,the rest of,the majority of + 名词”构成的短语以及由“分数或百分数+名词”构成的短语作主语，其谓语动词的数要根据短语中后面名词的数而定。如：There are a lot of people in the classroom./ The rest of the lecture is wonderful./ 50% of the students in our class are girls.
注意：a number of“许多”，作定语修饰复数名词，谓语用复数;the number of“……的数量”，主语是number，谓语用单数。
8.在倒装句中，谓语动词的数应与其后的主语一致。如：There comes the bus./ On the wall are many pictures./ Such is the result./ Such are the facts.