主語と述語の対応関係

and で結ばれた主語が同一人物（物）を表すときは、動詞は単数形をとる。

Curry and rice is served. （カレーライスが提供される。）
A poet and writer is present. (詩人でもあり、作家でもある人が出席している。)
and で結ばれた主語に every, each, noが付くときは、動詞は単数形をとる。

Each boy and each girl wears a cup.
No umbrella and no parasol was brought here.
either A or B; Neither A nor B: Bが動詞を支配する。

Either you or I am to go.
Neither you nor he has to go. (君も彼も行かなくてもよい。：全部否定)
not only A but also B: Bが動詞を支配する。

Not only Tom but also I am interested in art.
not A but B: Bが動詞を支配する。

Not you, but he knows the fact well.
A as well as B: Aが動詞を支配する。

Tom as well as you is tired.
half, part, portion （部分）, rest（残り）, lot（たくさん）などは、数に関するときは複数として扱い、量に関するときは、単数として扱う。

Half of the pears are rotten.
Half of the cake is mine.

Part of the crew were saved.
Peat of the money was wasted.

The rest of them are wrong.
The rest of the beer was drunk by him.

A lot of books were published.
A lot of sugar is left.

衆多名詞の単数形主語は複数動詞と結びつく。（衆多名詞については、「冠詞 (article)と名詞(noun)」のページも参照。）

The audience were deeply impressed. （聴衆は深い感銘を受けた。）
All the crew were welcomed.　（乗組員はみな歓迎された。）
The committee are at table. 　（委員達は食事中だ。）

衆多名詞	単純集合名詞
His family are all well.	His family is large.
Most of the crew were saved.	The crew consists of 30 sailors.
The audience were moved.	There was a small audience.

一個の概念を表す複数形主語は単数動詞と結びつく。複数形主語が、一個の概念を表すか否かは、文意・文脈によって判断されなければならない。

Ten miles is a long distance.
Three weeks have passed since his marriage.
The United States is a republic.
多くの学問の名前は複数形をとるが、一個の概念を表すとして、単数として用いられる。

physics, economics, politics, ethics, metaphysics (形而上学), mechanics, linguistics （言語学）,phonetics（音声学）, acoustics（音響学）,

*単数形をとる学問の名前もある。：logic, arithmetic, music

Physics is hard to master.
Economics interests me. （私は経済学の興味がある。）