用作副词(adv.)

Once or twice she looked over her shoulder at me.有一两次她回头看看我。

She had not once spoken to him all the evening.整整一晚上,她都没有跟他讲过一次话。

I see them about once a fortnight.我大约两星期见他们一次。

Once we pved in London.我们曾经住在伦敦。

用作副词(adv.)

I have been there once.
我到过那儿一次。

I once went around the world.
过去我周游过全球。

用作连词(conj.)

Once you begin, you must continue.
一旦开了头,你就必须继续下去。

Once you have taken the examination, you'll be able to relax.
你一旦考过试,就可以轻松一下了。

Once you have promised you must do it.
你既已答应,就应该去做。

Once inside her bedroom, she began to cry.
一走进卧室,她就哭了。

用作名词(n.)

Once is enough for me.
我一次就够了。

She's only done it the once so don't be too angry.
她只做过这一次,所以不要太生气。

conj.(连词)

once用作连词时可引导时间状语从句和条件状语从句。用于前者时意为“一旦…就…”,所引导的从句多很短; 用于后者时意为“只要”,这种条件从句似带有时间条件的含意。

once引导的从句中有些部分可以省略。

用作副词(adv.)

Once or twice she looked over her shoulder at me.有一两次她回头看看我。

She had not once spoken to him all the evening.整整一晚上,她都没有跟他讲过一次话。

I see them about once a fortnight.我大约两星期见他们一次。

Once we pved in London.我们曾经住在伦敦。

用作副词(adv.)

I have been there once.
我到过那儿一次。

I once went around the world.
过去我周游过全球。

用作连词(conj.)

Once you begin, you must continue.
一旦开了头,你就必须继续下去。

Once you have taken the examination, you'll be able to relax.
你一旦考过试,就可以轻松一下了。

Once you have promised you must do it.
你既已答应,就应该去做。

Once inside her bedroom, she began to cry.
一走进卧室,她就哭了。

用作名词(n.)

Once is enough for me.
我一次就够了。

She's only done it the once so don't be too angry.
她只做过这一次,所以不要太生气。

【近义词】

adv.
• at one time