it"s...time to do做某事的时间到了 It is time to go to school It is time for +名词It is time for school .have fun doing sth had fun doing sth will have fun doing sth 不用考虑have的形式...
He was playing at this time yesterday. 昨天这是正在玩耍。这是过去进行时态。进行时态结构:be +V-ing ,过去进行时,就是把be 变成过去式,根据主语的人称和数在判断是用was,还是用were。时态讲的是动作发生的时间。发生在过去某个时间的,就用一般过去时。动词就是过去式。不定式,构成:to +动词 原...