双词短语是用连词and把两个单词连接起来组成的短语，这种短语常常是习语，语序比较固定，比如我们常说的it rains cats and dogs, 是下倾盆大雨的意思。还有trial and error是反复试验的意思。Odds and ends 则是指零星杂物。
比如：
let’s get the main thing packed; we can do the odds and ends latters. 双词短语的语序不能颠倒说。
再有，give and take, 表示互谅互让，比如：Every relationship needs a bit of give and take to be successful.
有些双词短语有一个很有意思的规律，是从发音上可以判断出来。
比如：
Tears are part and parcel of growing up. Part and parcel是part of 的意思，也可以翻译成“属于”。
The boss was ranting and raving at us. Rant是咆哮的意思，rave是疯狂。和在一起表示very angry非常生气。
The old cottage has gone to rack and ruin. Go to rack and ruin基本已经形成了固定的词组，表示decayed，走向毁灭，走向灭亡。
有些介词组合起来同样构成双词短语。
比如：
There are cafes here and there. Here and there表示scattered round到处的意思。
I’ve been running back and forth all day. Back and forth表示“来来回回”。同样的，to and fro同样可以表示来来回回的意思。
He is unemployed and down and out. Down and out 表示“穷困潦倒”。
She ran up and down the street. Up and down 表示“上上下下”。
