diamond cuts diamond. 強中自有強中手。

　　do as the romans do. 入鄉(xiāng)隨俗。

　　do as you would be done by. 己所不欲，勿施于人。

　　doing is better than saying. 與其掛在嘴上，不如落實在行動上。

　　do it now.機不可失，時不再來。

　　nothing by halves. 凡事不可半途而廢。

　　don’t claim to know what you don’t know.不要不懂裝懂。

　　don’t have too many irons in the fire. 不要攬事過多。

　　don’t make a mountain out of a molehill. 不要小題大做。

　　don’t put off till tomorrow what should be done today.今日事，今日畢。

　　don’t put the cart before the horse. 不要本末倒置。

　　don’t trouble trouble until trouble troubles you.不要自找麻煩。

　　don’t try to teach your grandmother to suck eggs.不要班門弄斧。

　　do well and have well. 善有善報。