单词盒子

when

W 开头单词

音标发音

  • 英式音标 [wɛn]
  • 美式音标 [wɛn]
  • 英式发音
  • 美式发音

基本解释

  • adv. 什么时候；什么情况下；什么场合下；（用于时间的表达方式之后）在那时，其时；当时，当场
  • pron. 什么时候；何时
  • conj. 在……时候；在……之后；在任何……时候；一……就； 考虑到，既然；虽然，然而，可是
  • n. 时间，时候；日期；场合

词源解说

  • 直接源自古英语的hwenne，意为何时。

同根派生

     

用法辨析

    adv. (副词)

  • when的基本意思是“什么时候”。可用作疑问副词,用来询问某事曾发生或将要发生的时间,引导特殊疑问句; 还可用作关系副词引导限制性定语从句、非限制性定语从句和表语从句,表示“是…时候的事”。

    • conj. (连词)

  • when可用作从属连词,引导状语从句,表示时间时作“当…时,在…的时候”解; 表示条件时作“如果,要是”解; 表示对比时作“既然,考虑到”解。当when所引导的从句的主语和主句的主语一致时,常将其主语、系动词或助动词省去,只留实义动词或表语,或者改写为短语。
  • when所引导的时间状语从句用一般现在时代替将来时,用现在完成时代替将来完成时。

英汉例句

    用作副词 (adv.)

  • When did you see him last?
    你上次是什么时候见到他的?

    • 用作连词 (conj.)

  • Often she will weep when alone.
    她一个人时常哭。

词组短语

    短语

  • Remember When 记得当时;曾几何时;记妥当时
  • Say When 酒斟够了请说一声;够了就说;够了就请告诉我
  • When Rendering 只有在最后渲染时才重新计算更新效果;渲染时
  • When all 此时;当所有
  • Use When 何时用;什么时候用

英英字典

    剑桥英英字典

  • at what time; at the time at which
  • what/which time
  • (CONSIDERING THAT) considering the fact that
  • (ALTHOUGH) despite the fact that

    • 柯林斯英英字典

  • You use when to ask questions about the time at which things happen.
  • If something happens when something else is happening, the two things are happening at the same time.
  • You use when to introduce a clause in which you mention something that happens at some point during an activity, event, or situation.
  • You use when to introduce a clause where you mention the circumstances under which the event in the main clause happened or will happen.
  • You use when after certain words, especially verbs and adjectives, to introduce a clause where you mention the time at which something happens.
  • You use when to introduce a clause that specifies or refers to the time at which something happens.
  • You use when to introduce the reason for an opinion, comment, or question.
  • You use when in order to introduce a fact or comment which makes the other part of the sentence rather surprising or unlikely.

专业释义

    语言学

  • 既然

    • 航空、航天科学技术

  • 时间

    The simulation results show that the identification rate can achieve 99 % and the average identification time is 1.8 ms,when position noise is in the max position error.
    仿真实验表明:当位置噪声在估计最大位置误差范围以内时,本算法识别成功率可达99%以上,平均识别时间为1.8 m s,很好地满足了星图识别的要求。