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。 9 B& l" e' M5 X' t1 T" g / P0 V7 u) }$ |: y" r" ^7 X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。1 ~! ?- }( z$ @- O
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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。 W V! b+ m5 |" E
' G) n0 [! \# X' P; N2 f下面是一个老外在网上出售仿真枪时作的说明: P& ~) O3 f; H9 ?2 X2 [, U/ ^ }& I! J2 \3 d( q; d5 I! f
This 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. * p' P6 z4 k/ j+ \2 s