除了片语动词、动词短语等之外，这里要介绍一种三位一体的词组，我把它们命名为“三合一惯用语”，由名词+名词、动词+动词、形容词+形容词以及副词+副词合组而成。有时两个词之间不用“ and”而用“or”。三合一惯用语数目不算多，但已渐渐在增长中，相当配合时尚，可以多加留意，尽量学用。
下面是些常见的例子：
㈠ 名词+名词
● rules and regulations(各种条例)
“One should pay attention to all the rules and regulations of a working place.”
● law and order(法律秩序;法纪)
“The police‘s job is to maintain law and order of a country.”
● facts and figures(事实和数字)
“Traditional teaching tends to cram students with facts and figures for memorisation and regurigitation.”
● do’s and dont‘s (应注意的事项)
“Try to be familiar with the do’s and dont‘s of an organisation.”
● merits and demerits(优缺点)
“To evaluate a system， one has to take into account both its merits and demerits.”
● bag and baggage(连同全部财物)
“The rascal was turned out of the room bag and baggage.”
● pros and cons(赞成和反对的理由)
“It is important to consider the pros and cons of a matter before coming to a decision.”
● doom and gloom(失望与不快)
“All the reports on world economy are full of doom and gloom.”
● ways and means (各种方法)
“Some addicts seem to have ways and means of getting the drugs for unending consumption.”