1) 代詞each和由every, some, no, any等構成的復合代詞作主語，或主語中含有each, every, 謂語需用單數。

Each of us has a tape-recorder.

There is something wrong with my watch.

2) 當主語是一本書或一條格言時，謂語動詞常用單數。

The Arabian Night is a book known to lovers of English.

<<天方夜譚>>是英語愛好者熟悉的一本好書。

3) 表示金錢，時間，價格或度量衡的復合名詞作主語 時，通常把這些名詞看作一個整體，謂語一般用單數。(用復數也可，意思不變。)

Three weeks was allowed for making the necessary preparations.

Ten yuan is enough.