对于区分 can 和 can't 有困难的人士,曾经有个建议说 用be able to和be unable to来代替。我也曾经这样说过。 F- i* u$ |/ m* L
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但是要分场合。因为be able to实际的含义是有能力做。要是忽视这个含义,就可能出错。8 }# \( Q6 |1 e+ e7 `: c( `
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比如,The rules can't be enforced. 要是给换一下,变成了 The rules are unable to be enforced. 这句话在逻辑上乱七八糟。因为rules本身没有什么能力去被执行。如果说 The manager was unable to enforce the rules. 逻辑上语法上都说得过去,可是被迫使用了主动语态,与原意不完全符合。. B o) d* `$ d) W
4 c. [1 X. T( A9 L2 UThis item cannot be made to fire and has never been capable of firing. The metal is not strong enough to hold a charge. For decorative purposes only. 1 c* O& s: m6 Y+ e- U7 l3 C; ~* a" ]+ ~
谨供参考。