一言为定英语

直接说deal 就行

That's / It's a deal.

A promise is a promise下面的也是That's settled then.;; count it as settled; It's a deal [whack].; once and for all; shake hands on sth.; take someone at his word; That's a bargain [whack].

It‘s a deal.A promise is a promise.

其实很简单，就干脆利落的一个Deal！就好了

That's settled.It‘s a deal.It's a date好多表示承诺的也能表示成一言为定吧,,比如You have my word.口语用的最多的是Deal.

make a deal成交；达成交易;