By the time he was 14,he was able to play the guitar.By the time不_英语解答

By the time he was 14,he was able to play the guitar.By the time不是加过去完成时吗?这句话怎么回事?难道是主句强调动作时才用过去完成,这里是状态就用一般过去就行了?麻烦讲清楚谢谢最好有例子

人气：465 ℃　时间：2020-03-27 01:34:51

解答

be able to 没有完成时的用法