once后面时态.１、Once he said that,I know he was lying.2.Once you have _英语解答

once后面时态.
１、Once he said that,I know he was lying.
2.Once you have make a promise,you must carry it out.
两句都对?once后面究竟完成时态还是一般时?

人气：159 ℃　时间：2020-01-29 17:53:59

解答

如果是过去的事,就用过去时,如句1.
如果是将来的事,就用一般现在时或现在完成时,如句2.
由once引导的句子属于“主将从现”,但一般现在时可以由现在完成时代替.