现在进行时介词请问:for+表示一段时间的短语since+表示过去时间点的语法since+表示过去事件终于从句ever,already,just,yet,before类似的这些介词应该怎麽用?

关键理解中文意思.类似中国话的.
since——从
ever——从来,一直
already——已经
just——刚刚,不过
yet——但是,没有
before——在什么之前
for——一段时间
Since I answered your question,I have learned more.
Have you understand it already?
I just said something strange.
I have't catched you yet.
类似的.