By와 until By the time …

By (+ a time) = "no later than":

• I mailed the letter today, so they should receive it by Monday. (= on or before Monday, no later than Monday)

• We'd better hurry. We have to be hom by 5:00.

(= at or before 5:00, no later than 5:00)

• Where's Sue? She should be here by now. (= now or before now - so she should have arrived already)

Until은 이와 같은 의미로 사용할 수 없습니다:

• Tell me by Friday whether or not you can come to the party. (not Tell me until Friday)

상황이 얼마나 오랫동안 지속되었는지를 이야기할 때 until(또는 till)을 사용합니다:

until과 by의 비교:

by the time something happened:

• (편지에서) I'm flying to Mexico this evening. So by the time you receive this letter, I'll be in Mexico City. (= I will arrive in Mexico City between now and the time you receive this letter.)

• Hurry up! By the time we get to the theater, the play will already have started.

by the time something happened (과거에 대해):

• Jane's car broke down on the way to the party last night. By the time she arrived, most of the guests had left. (= It took her a long time to get to the party, and most of guests went home during this time.)

• I had a lot of work to do yesterday evening. I was very tired by the time I finished. (= It took me a long time to do the work, and I became more and more tired during this time.)

• We went to the theater last night. It took us a long time to find somewhere to part the car. By the time we got to the theater, the play had already started.

by then 또는 by that time:

• Jane finally arrived at the party at midnight, but by then (or by that time), most of the guests had left.