when

音標(biāo)發(fā)音

• 英式音標(biāo) [w?n]
• 美式音標(biāo) [w?n]
• 英式發(fā)音
• 美式發(fā)音

基本解釋

• adv. 什么時(shí)候；什么情況下；什么場(chǎng)合下；（用于時(shí)間的表達(dá)方式之后）在那時(shí)，其時(shí)；當(dāng)時(shí)，當(dāng)場(chǎng)
• pron. 什么時(shí)候；何時(shí)
• conj. 在……時(shí)候；在……之后；在任何……時(shí)候；一……就； 考慮到，既然；雖然，然而，可是
• n. 時(shí)間，時(shí)候；日期；場(chǎng)合

詞源解說(shuō)

• 直接源自古英語(yǔ)的hwenne，意為何時(shí)。

同根派生

• when相關(guān)詞

用法辨析

adv. (副詞)

• when的基本意思是“什么時(shí)候”。可用作疑問(wèn)副詞,用來(lái)詢問(wèn)某事曾發(fā)生或?qū)⒁l(fā)生的時(shí)間,引導(dǎo)特殊疑問(wèn)句; 還可用作關(guān)系副詞引導(dǎo)限制性定語(yǔ)從句、非限制性定語(yǔ)從句和表語(yǔ)從句,表示“是…時(shí)候的事”。

conj. (連詞)

• when可用作從屬連詞,引導(dǎo)狀語(yǔ)從句,表示時(shí)間時(shí)作“當(dāng)…時(shí),在…的時(shí)候”解; 表示條件時(shí)作“如果,要是”解; 表示對(duì)比時(shí)作“既然,考慮到”解。當(dāng)when所引導(dǎo)的從句的主語(yǔ)和主句的主語(yǔ)一致時(shí),常將其主語(yǔ)、系動(dòng)詞或助動(dòng)詞省去,只留實(shí)義動(dòng)詞或表語(yǔ),或者改寫(xiě)為短語(yǔ)。
• when所引導(dǎo)的時(shí)間狀語(yǔ)從句用一般現(xiàn)在時(shí)代替將來(lái)時(shí),用現(xiàn)在完成時(shí)代替將來(lái)完成時(shí)。

• when使用方法
• when詳細(xì)辨析

英漢例句

用作副詞 (adv.)

• When did you see him last?
  你上次是什么時(shí)候見(jiàn)到他的?

用作連詞 (conj.)

• Often she will weep when alone.
  她一個(gè)人時(shí)?？?。

• when更多例句

詞組短語(yǔ)

短語(yǔ)

• Remember When 記得當(dāng)時(shí);曾幾何時(shí);記妥當(dāng)時(shí)
• Say When 酒斟夠了請(qǐng)說(shuō)一聲;夠了就說(shuō);夠了就請(qǐng)告訴我
• When Rendering 只有在最后渲染時(shí)才重新計(jì)算更新效果;渲染時(shí)
• When all 此時(shí);當(dāng)所有
• Use When 何時(shí)用;什么時(shí)候用

• when更多詞組

英英字典

劍橋英英字典

• 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.

• when劍橋字典
• when柯林斯字典

專(zhuān)業(yè)釋義

語(yǔ)言學(xué)

• 既然

航空、航天科學(xué)技術(shù)

• 時(shí)間

  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.
  仿真實(shí)驗(yàn)表明:當(dāng)位置噪聲在估計(jì)最大位置誤差范圍以內(nèi)時(shí),本算法識(shí)別成功率可達(dá)99%以上,平均識(shí)別時(shí)間為1.8 m s,很好地滿足了星圖識(shí)別的要求。