byは軆??め切り「～までに」、untilは期間「までずっと」
A by B
A--->B
She stayed by 4 o'clock.（駄目・??
She will come by 4 o'clock. 4時まで縺?
A until B
A<--->B
She stayed until 4 o'clock. 4時までずっ縺?
She will come until 4 o'clock.（駄目・??
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■例1
Please wait until I come. 縺?OK
She will come until we get there. は饅??逶?
She will not come until we get there. 縺?OK
She will come before we get there. 縺?OK
She will come by the time we get there. 縺?OK
by は前置鐔??なので藹??ろに軆??をつける場合は、by the time ---のようにします。
until は前置鐔??と接続詞の両方があるので、後ろには名詞、節の両方をつけることができる。
byはある時点、untilは軆??続
■例2
I'll be there until three o'clock. 3時まで藹??ます
I'll be there by three o'clock. 3時までには到着します
■例3
Postpone until --- 縺?OK、 Postpone by --- 駄逶?