作业帮since和until(since和until)
来源：学生作业帮 编辑：作业帮 分类：英语作业 时间：2024/05/15 23:47:09
请问since的用法的中文解释是什么？until也是这个问题？请尽快回答，谢谢！
解题思路： 学习单词时注意词义，同时注意要多通过典型的例句进行掌握。
解题过程：
since的用法主要有两点：一是表示“自从……以来”，二是表示“既然”之意。下面谈谈since作连词引导时间状语从句的用法。
一、若since引导的状语从句的谓语动词是终止性的过去时，则从句表示的时间是“从动作开始的那一时刻起”。如：
He has studied very hard since he came to our school.自从他来到我们学校，他学习就非常努力。
We have been missing them since they left here自从他们离开这里，我们就一直很想念他们。
这是最常见的一种用法，此处不再多述。
二、若since引导的状语从句的谓语动词是持续性动词或表示状态的动词的过去时时，则从句表示的时间是“从那持续动作或状态结束时算起”。如：
I haven’t heard any noise since I slept. Sleep 为持续性动词，sleep的动作结束时，即“醒来”时，这句应译为“我醒后还未听到任何声音”。
How long is it since you lived in Shanghai?你离开（没住在）上海多久了？
It is half a month since he was a League member.他退团（不当团员）半个月了。
It’s been quite some time since I was last in London我离开伦敦已很长时间了。
比较：He has written to me frequently since I was ill.自从我病愈以来，他屡次给我写信。（从句谓语为状态动词）
He has written to me frequently since I fell ill.自从我生病以来，他就屡次给我写信。（从句谓语为终止性动词）
三、若since引导的状语从句的谓语为持续性动词的现在完成时，则表示动作和状态延续到现在（说话时刻），其表示的时间的起点应从动作发生之时算起。如：
I haven’t heard from him since he has lived there。
这里has lived表示动作的持续性，时间的起点应从：“开始居住”时算起。因此此句可理解为“自从他（开始）住在那儿起，我就一直没收到他的来信”。
Since we have owned a car, we have gone camping every year。自从我们自己有了汽车，我们每年都去野营。
试比较：1. Since I’ve been at this school, we have had three headmasters.自从我到这所学校，我们已换了三个校长了。
Since I was at this school, they have had three headmasters.自从我离开这所学校，他们已换了三个校长了。
2.He has never been to see me since I have been ill. 自从我生病以来，他从未来看过我。
He has never been to see me since I was ill. 自从我病愈以来，他从未来看过我。
由此可见，since引导的从句持续动词的一般过去时和现在完成时所表示的意思恰好相反。换言之，前者以肯定的语法形式反映着否定的逻辑内容，而后者的形式与内容是一致的。
至于It is +一段时间+since…的句型与It has been +一段时间+since…意思相同。前者是规范说法，后者是口语说法。
应注意的是，在这种结构中，since引导的从句绝对不能用否定式的谓语动词来表示否定意义，下面两句都错了：
It is a long time since he didn’t study English.
It’s two months since you didn’t come to see me.
正确的说法为：
It’s a long time since he studied English 他好久没学英语了。
You haven’t come to see me for two months. 你有两个月没来看我了。
until的用法：
连词 conj. 直到…为止
up to the time when
· I'll wait until he arrives and then I'll leave.
我要等他来以后再离开。
· Go straight on untill you come to a large red building.
一直往前，走到一幢高大的红色建筑物为止。
· The teacher kept on asking the students questions until the bell rang.
老师反复向学生提问，直到下课铃响。
连词 conj. （在否定句中）在…之前
· I shan't do that until you come back.
在你回来之前，我不会干那件事。
· We won't come to any decision until we have had a chance to discuss the problem thoroughly.
我们有机会充分讨论这个问题再决定下来。
·
介词 prep. 直到…为止
· It was only a week until Christmas.
离圣诞节只有一个星期了。
· She will stay until Saturday.
她要一直呆到星期六。
介词 prep. 在…之前；不到…（不）
· I can't come until tomorrow.
我得明天才能来。
· Not until noon did it stop raining.
直到中午雨才停止。
祝你的英语成绩越来越棒！
假期愉快！
最终答案：略
解题过程：
since的用法主要有两点：一是表示“自从……以来”，二是表示“既然”之意。下面谈谈since作连词引导时间状语从句的用法。
一、若since引导的状语从句的谓语动词是终止性的过去时，则从句表示的时间是“从动作开始的那一时刻起”。如：
He has studied very hard since he came to our school.自从他来到我们学校，他学习就非常努力。
We have been missing them since they left here自从他们离开这里，我们就一直很想念他们。
这是最常见的一种用法，此处不再多述。
二、若since引导的状语从句的谓语动词是持续性动词或表示状态的动词的过去时时，则从句表示的时间是“从那持续动作或状态结束时算起”。如：
I haven’t heard any noise since I slept. Sleep 为持续性动词，sleep的动作结束时，即“醒来”时，这句应译为“我醒后还未听到任何声音”。
How long is it since you lived in Shanghai?你离开（没住在）上海多久了？
It is half a month since he was a League member.他退团（不当团员）半个月了。
It’s been quite some time since I was last in London我离开伦敦已很长时间了。
比较：He has written to me frequently since I was ill.自从我病愈以来，他屡次给我写信。（从句谓语为状态动词）
He has written to me frequently since I fell ill.自从我生病以来，他就屡次给我写信。（从句谓语为终止性动词）
三、若since引导的状语从句的谓语为持续性动词的现在完成时，则表示动作和状态延续到现在（说话时刻），其表示的时间的起点应从动作发生之时算起。如：
I haven’t heard from him since he has lived there。
这里has lived表示动作的持续性，时间的起点应从：“开始居住”时算起。因此此句可理解为“自从他（开始）住在那儿起，我就一直没收到他的来信”。
Since we have owned a car, we have gone camping every year。自从我们自己有了汽车，我们每年都去野营。
试比较：1. Since I’ve been at this school, we have had three headmasters.自从我到这所学校，我们已换了三个校长了。
Since I was at this school, they have had three headmasters.自从我离开这所学校，他们已换了三个校长了。
2.He has never been to see me since I have been ill. 自从我生病以来，他从未来看过我。
He has never been to see me since I was ill. 自从我病愈以来，他从未来看过我。
由此可见，since引导的从句持续动词的一般过去时和现在完成时所表示的意思恰好相反。换言之，前者以肯定的语法形式反映着否定的逻辑内容，而后者的形式与内容是一致的。
至于It is +一段时间+since…的句型与It has been +一段时间+since…意思相同。前者是规范说法，后者是口语说法。
应注意的是，在这种结构中，since引导的从句绝对不能用否定式的谓语动词来表示否定意义，下面两句都错了：
It is a long time since he didn’t study English.
It’s two months since you didn’t come to see me.
正确的说法为：
It’s a long time since he studied English 他好久没学英语了。
You haven’t come to see me for two months. 你有两个月没来看我了。
until的用法：
连词 conj. 直到…为止
up to the time when
· I'll wait until he arrives and then I'll leave.
我要等他来以后再离开。
· Go straight on untill you come to a large red building.
一直往前，走到一幢高大的红色建筑物为止。
· The teacher kept on asking the students questions until the bell rang.
老师反复向学生提问，直到下课铃响。
连词 conj. （在否定句中）在…之前
· I shan't do that until you come back.
在你回来之前，我不会干那件事。
· We won't come to any decision until we have had a chance to discuss the problem thoroughly.
我们有机会充分讨论这个问题再决定下来。
·
介词 prep. 直到…为止
· It was only a week until Christmas.
离圣诞节只有一个星期了。
· She will stay until Saturday.
她要一直呆到星期六。
介词 prep. 在…之前；不到…（不）
· I can't come until tomorrow.
我得明天才能来。
· Not until noon did it stop raining.
直到中午雨才停止。
祝你的英语成绩越来越棒！
假期愉快！
最终答案：略