since后面加什么时态
since he____(be)here
since they_________(leave)China 展开
since,副词 adv(常用于现在完成时或过去完成时),介词(常用于现在完成时或过去完成时)。
since后面从句用一般过去时。
例:I‘ve made great progress in English since I came to this school.
自从我来到这个学校以来;我在英语上取得了巨大的进步。
since+延续动词
since后面接延续动词时,用一般过去时态或现在完成时态均可,意但思不一样:
1、用一般过去时态,表示从句动作”结束“以来,主句活动在持续;
2、用现在完成时态,表示从句动作”开始“以来,主句活动在持续。
例:It's been three years since I worked in this company.
我不在这家公司工作有三年了。
It's been three years since I have worked in this company.
我在这家公司工作有三年了。
另外,since引导的从句除了用一般过去时态或完成时态外,也可以根据具体语境用完成进行时态。
参考资料:百度百科-since
1、当since表示“自从”时,不管它是用作介词、连词还是副词,它通常都要与现在完成时(since前)连用。如:
I’ve worn glasses since my childhood. 我从小就戴眼镜。
2、当主句表示“多长时间”时,动词可用一般现在时(当然也可用现在完成时)。如:
It’s a long time since I met you last. 好久不见了。
since, after, in其区别是:
1、after可表示从过去时间算起的一段时间之后,往往与过去时态连用(若接表示时间点的词,也可与将来时态连用);
2、in则表示从现在时间算起推移到将来的一段时间之后,一般与将来时态连用;
3、since所表示的时间往往是从过去某一点时间一直延续到说话的时间,因而一般与完成时态连用。
since they____left_____(leave)China
since是一个从属连词,它可以引导时间状语从句‘原因状语从句和方式状语从句等,从句既可置于主句之前,亦可置于主句之后.
1.从属连词since引导时间状语从句,意谓”自从......以来”.since引导的时间状语从句有两种用法:
第一种是从句用现在完成时,从句用一般过去时,表过去某个时间开始直到现在.如:
(1)I have not laughed since I became deaf . 自从我聋了以后我就没有大笑过.
(2)It's been years since I enjoyed so much as last night . 我已经好多年没有像昨晚那样痛快了.
since经常用ever加强语气.如:
(3)We've been friends ever since we met at school . 我们自从同校相识后就一直是朋友.
第二种是主句用过去完成时,从句用一般过去时或过去完成时,表过去某个时间知道过去某个时间.如:
(4)Since she came to me , we had been happy . 自从她来到我这里,我们一直很快活.
(5) Two weeks had passed since Martin had seen him . 自从马丁见到他以后,两周已经过去了.
2.从属连词since引导原因状语从句,意谓”既然”‘”因为”‘”由于”.如:
(6)Since you are going , I will go too . 既然你要去,我也要去吧.
(7)Why do people come to his lectures since he is difficult to understand ? 既然他的话难听懂,为什么人们还要来听他的演讲呢?
(8)Aircraft noise is a particular problem here since we're close to Heathrow Airport . 由于我们*近希思罗机场,这里的飞机噪声就成了一个严重的问题.
3.since亦可用作介词.如:
(9)We hadn't seen each other since Oxford . 我们自从牛津别后就彼此没有见过面.
(10) I have not heard from him since writing last . 自上次写信以后,我没接到过他的信.
与after和before一样,since既可用作从属连词,亦可用作介词.但是这三个词后跟的-ing形式,必须看作介词和动名词组合,不能看作从属连词引导的省略分句,因为这里的-ing形式可以用物主代词修饰.如:
(11) Since my coming to London , I have not been well. 自从我来伦敦以后就一直没有好过.
4.since亦可用作副词.如:
(12) Her husband died ten years ago but she's since remarried . 她的丈夫于十年前去世,但是她后来又结婚了.
(13) He came to England three years ago and has lived here ever since . 他三年前来到英国,从那以后就一直住在这里.
left
1)since
+过去一个时间点(如具体的年、月、日期、钟点、1980,
last
month,
half
past
six)。例如:
I
have
been
here
since
1989.
1989起,我一直在这儿。
2)since
+一段时间+
ago。例如:
I
have
been
here
since
five
months
ago.
我在这儿,已经有五个月了。
3)since
+从句。例如:
Great
changes
have
taken
place
since
you
left.
你走后,变化可大了。
Great
changes
have
taken
place
since
we
were
here.
我们走后,变化可大了。
4)It
is
+一段时间+
since从句。例如:
It
is
two
years
since
I
became
a
postgraduate
student.
我考上研究生有两年了。