完成时。ever since可作为副词，解释“此后”（就一直……），是完成时的标志。He fell ill at Christmas and has been ill ever since.他在圣诞节生病了此后就一直不适。
ever since释义：自从；从那时到现在；自…以后；从…起
ever since的用法
1.ever since的结构：(作为连词)=since完成时态----ever since+主+动词简单过去式
例：I have known him ever since he was a child. 他从小我就认识他了。这种用法同since差不多，不过ever since比since用得少。
再如：We have lived in Shanghai ever since we came to China.(自从我们来到中国之后就住在上海。)
2.以上所说的ever since作为连词。ever since也可作为副词，解释“此后”(就一直...)。例：
1)He fell ill at Christmas and has been ill ever since. 他在圣诞节生病了此后就一直不适。(has + be ill)
2)He left home last year and has been away ever since. 他去年离家走了，此后一直在外面。(has+be away)
3)He fell off his horse a week ago and has been in bed ever since. 一周前他从马背上跌下来，从那以后就一直躺在床上。
4)He went to Turkey in 1950 and has lived there ever since. 他在1950年去土耳其，此后就一直住在那里。