could也能表示过去的一般的允许:. y0 H9 O5 r- `) ^$ H
On Sundays we could(=were allowed to)stay up late. % ~7 X. A0 `5 W; i3 n" ~ 星期天晚上我们能到较晚才睡。; X4 e5 ?- Q8 h6 j: y
当某一具体行为获准并付诸实施时,就必须用was/were allowed代替could:/ Y8 n3 L4 B5 y7 t0 r
I had a visa so I was allowed to cross the frontier.& `: e C$ ]) B) E& A
我有签证,所以我被允许越过边界。 : d7 @* U% v; l1 j/ [ A1 F couldn't的用法比could要稍为广泛一些: 5 }" {$ K n9 L0 X' |& [ We couldn't bring our dog into the restaurant. - G5 N; J0 |8 p2 V" @ 我们不能把狗带进饭馆里。 , s6 l9 K1 z9 q- { 与此相反的意思应当用allow表示:* K+ o$ n/ z$ J
We were allowed to bring… ( N3 ^9 _- C2 x, Q! l M& @ 允许我们把狗带进……, ; _5 p7 }1 J" Z( J 如欲使用完成时和被动语态,则必须用 allowed:: f. O( }9 F. V+ [( ~! E3 E
Since his accident he hasn't been allowed to drive.+ \$ [$ v! a7 S3 ?
自从他出了车祸以后就不允许他再开车了。* B; h7 X; x8 }1 }- r& R5 w! z! @
As a child he had been allowed to do exactly what he liked. 1 w! F) @2 K- e, I$ h. ` 他小时候,容许他爱干什么就干什么。