谓语受主语支配,它必须在人称和数等方面与谓语保持一致。
语法形式上一致
单数的名词、代词、动词不定式、动名词短语或从从句作主语时,谓语动词用单数。
What I hate most is telling lies.
To become a doctor is his ambition.
Whether she comes or not is of no matter
what引导的'从句作主语,如果它后面的表语是复数形式,谓语动词亦可以用复数。
What I said is right.
What we need badly here are doctors.
由and连接并列主语时:
Swimming in the summer and skating in the winter are my hobbies
In the city are to be found both the most renowned scholar and the scoundrels
a block and tackle;the needle and thread;brandy and soda;sale and water;law and order;a cup and saucer; the ebb and flow ; the rope and pulley
watch and chain;soap and water;etc。
There is my watch and chain on the dressing-table.
若and后面的名词前有冠词或物主代词修饰,谓语动词用复数形似。
The bread and the butter are on sale.
由and连接的并列单数主语前有each, every, no , many a 等修饰时,谓语动词用单数形式。