by the time

IPA/baɪ ðə tˈaɪm/
IPA/baɪ ðə tˈaɪm/

by the time — 慣用語

1. used to say that a situation or action has already been completed before or at t

1.慣用語B1
釋義

等到⋯⋯時

表示某事在另一事件發生前或發生時已完成

used to say that a situation or action has already been completed before or at the moment when another event happens, often emphasizing that the first event is finished before the second begins.

例句

By the time the firefighters arrived, the barn had already collapsed.

消防隊趕到時，穀倉已經倒塌了。

past perfect in main clause for completed past event

By the time the concert ended, the last train had already left the station.

演唱會結束時，最後一班列車已經離站了。

同義詞
  • before

    stronger emphasis on one event happening earlier than another; 'by the time' adds the nuance of completion up to a deadline or reference point

  • when

    can sometimes substitute in informal use, but 'when' does not carry the meaning of completion before a reference point

  • by

    a shorter equivalent used before a specific time or age ('by age 30' = 'by the time he was 30'), but cannot be used before a full clause

文法句型

by the time + [clause], [main clause with perfect tense]

用法筆記

The time clause after 'by the time' uses a simple tense (past for past reference, present for future reference). The main clause typically uses a perfect tense — past perfect for completed past events and future perfect for future events. Example: 'By the time she arrives, I will have cooked dinner.' (NOT 'I will cook dinner.')

常見錯誤

❌By the time I got home, I cooked dinner.
✅By the time I got home, I had already cooked dinner.
💡When 'by the time' refers to the past, the main verb usually needs past perfect to show the action was completed before the time reference.
❌By the time she will arrive, I will finish.
✅By the time she arrives, I will have finished.
💡The clause after 'by the time' uses present tense even when referring to the future; the future meaning goes in the main clause with future perfect.