当用since表“自从”时，since所在的句子就要用完成时吗

Question

如题所述

Answer 1

不一定。
放在句首时,有时表示“既然”，就不用完成时态。
如：since
you
are
here,
I
shall
tell
you
the
news.
在句中后面是过去式，过去时间，前面的主句才用现在完成时态。

Answer 2

用法包括两点，一是如果意为自从，后面接表示过去的时间状语或状语从句，这时主句使用现在完成时。二是意为既然，引导原因状语从句，时态要看具体意思。比如1.he
has
lived
here
since
he
was
eight.2.since
everyone
is
here,we
will
being
the
meeting
.

Answer 3

一般情况下是这样的,since+过去时是现在完成时的一个时间状语，主句应该使用现在完成时。
有一个例外：It
is+时间段+since...这个句型可以代替It
has
been+时间段+since...。例如：It
has
been
three
years
since
we
saw
each
other
last
time.可以替换为：It
is
three
years
since
we
saw
each
other
last
time.

Answer 4

你好。句型结构是：
现在完成时（主句）+
since
+
一般过去时（从句）
例句：
She
has
been
with
us
SINCE
she
arrived
here
five
minths
ago.
(主句)
（连接词）
（从句）本回答被提问者采纳