兩者在用法上應注意以下幾點：
1.相關主句謂語必須是持續(xù)性動詞,若是終止性動詞,則應為否定式（因為終上性動詞一旦被否定就成為狀態(tài),便可持續(xù)）.如：He waited until she was about to leave.他等著一直到她準備離開.She didn’t marry until she was over fifty.她直到50多歲才結婚.
2.引導時間狀語從句時,其謂語要用現(xiàn)在時表示將來意義.如：I won’t leave until he comes back tomorrow.我要等他明天回來后再走.Continue in this direction until you see a sign.一直朝著這個方向走就看見指示牌了.
3.有時其后可跟副詞或介詞短語等.如：He has been ill until recently.他最近一直生病.Until when are you going to stay here?你在這兒要待到什么時候?We didn’t eat till past midnight.直到午夜過后我們才吃飯.She won’t go home until after the exam.她要考完試之后再回家.如果語境的`需要,有時甚至可以接帶有“引導詞”的從句.如：Don’t leave until after I’ve spoken to you.我和你說完后再離開.