136 can be able的各种形式


can be+形容词 able在此互相关联;后者补充 can所没有的形式,并可以替换can用于现在时和过去时,因此有以下各种形式:

不定式:to be able

过去分词: been able

将来时只有一个形式,因为can除了表示许可时外不能用于将来时,但是在条件语气中则有两种形式:could would beable

be able的所有其他时态,都按照普通动词的规则来构成:

现在完成时:have been able

过去完成时:had been able

否定疑问式:could you not?/couldn't youwere you not?/weren't youablewill you not?/won't you be able?等

canbewillshall not have都可以按通常方法缩略:

I wasn't able he wont be able I've been able


be able后面带有 to的不定式。