我来帮您回答：
1、since ever 翻译为自从,与现在完成时态或过去完成时态连用.
（这与ever since 略有不同,ever since+ 过去时的句子：◆ever since I was at school .自从我上学以来.）
◆ He has lived there since ever.=Since ever,he has lived there.从那以后,他就住在那儿.
2、since then 意思是：从那以后直到现在,用于现在完成时.◆ I saw them at Christmas but haven't heard a thing since then.
◆ That was years ago.I've changed jobs since then.
所以他们的差别就在于用法不一样.学习语言不能只记意思,还要看用法,所以多差字典哦!
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