3. 動名詞，不定式，從句作主語的時候，謂語動詞一般要用單數

To see is to believe.

Swimming is a good way to keep health.

Who is her father is not known.

4. 集體名詞作主語時

a) mankind/humanity/man(人類)作主語的時候，謂語動詞一般用單數形式

Only man knows how to cook.

b) 由people, police, cattle, youth等集體名詞作主語的時候，謂語動詞用復數形式

The cattle are grazing in the field.

c) Family, croud, class, public, enemy等集體名詞作主語的時候

i. 若當整體看，則謂語動詞用單數形式

Our class is very diligent.

ii. 若他們表示的人或者事物當作若干個個體來看，謂語動詞則用復數形式

When I came into the room, his family were watching TV.

iii. A family/group/class作主語時，謂語動詞用單數

families/groups/classes作主語時，謂語動詞用復數

A group is coming to the zoo.

5. 其他情況

a) 主語為表示距離、時間、長度、價值、金額、重量等復數名詞的時候，謂語動詞用單數形式

3 kilometers is not very far.

Three times three makes nine.

b) one, every/each one, each, anyone, either, neither + of + 復數名詞

謂語動詞一般用單數形式，因為of之后的復數名詞不是主語而是介詞of的賓語，of前面的one, every one … 才是主語

Neither of them is right.

Each of them has a slide.

c) none of + 不可數名詞——謂語動詞用單數形式

none of + 可數名詞——謂語動詞單復均可

None of that money in the desk is his.

None of his classmates knows the truth.

d) 分數或百分數 + of + 詞組

分數或百分數+ of +詞組作主語時，謂語動詞的數取決于of后的名詞或者代詞的數;若名詞或代詞是復數，謂語動詞用復數，若名詞或代詞是單數，則謂語動詞用單數

Three-thirds of the surface of the earth is sea.

Tens of tons of waste goes into the air with the smoke every day.

e) more than one +(單數名詞)+單數動詞

more than two +(復數名詞)+復數動詞

More than one white rose has bloomed.

More than two white roses have bloomed.

f) a (great) number of + 復數名詞 ——用復數動詞

the number of + 任何名詞 —— 用單數動詞

A great number of tourists have been to the Great Wall.

The number of students in the computer class is limited to ten.

g) the + 形容詞，表示一類人 ——謂語動詞用復數

the + 形容詞，表示一類物 ——謂語動詞用單數

The rich are for the decision but the poor are against it.

The beauty is here.

h) every, any, some, no 構成的復合詞someone, somebody, something ，no one, nobody, nothing everyone, everybody, everything anyone, anybody, anything這些復合詞作主語的時候，謂語動詞用單數形式

Everyone in the class was surprised at the news.

Listen, someone is knocking at the door.