考研英语的语法速成：谓语动词用单数的情况

　　1.动名词短语、不定式短语、名词性从句做主语，谓语用单数。如：

　　Buying clothes is often a time-consuming job because those clothes that a person likes are rarely the cones that fit him or her.

　　To understand the situation completely requires more thought than has been given thus far.

　　2.表示时间、距离、金额、重量、面积、体积、容积等度量的名词短语做主语时，谓语用单数。

　　Two weeks was too long

　　Five times five makes twenty five

　　3.一般用and连接的两个单词或短语做主语时候，谓语用复数，但是下面用and连接的主语表示一个概念，谓语用单数：

　　law and order 法制 soap and water 肥皂水

　　a cup and saucer 茶杯碟子 fork and knife 刀叉

　　the needle and thread 针线 trial and error 反复尝试，不断摸索

　　horse and carriage 马车 time and tide 岁月

　　bread and butter 奶油面包 the ebb and flow 盛衰，潮涨潮落

　　如： If law and order not preserved, neither the citizen nor his property is safe.

　　A. is B. are C. was d. were

　　答案：A。

　　4.表示学科和某些疾病名称的名词是复数形式，作主语时候谓语动词用单数形式

　　Linguistics is a branch of study on human language.

　　5.有些名词形式上是复数，意义上是单数，根据意义一致原则动词用单数

　　The chaos was stopped by the police

　　The news is a great encouragement to us

　　A series of debates between the lectures was scheduled for the next weekend.

　　6.用and 连接的成份表示一个单一概念时候，动词谓语用单数形式

　　Bread and butter is our daily food

　　Time and tide waits for no man