时间状语从句，用表示时间的连词连接一个句子作状语，这样的从句就是时间状语从句。在写作中，如果要参照一段时间或另一件事来说明某事发生的时间，即可用时间状语从句。
常见引导词：
when(在……时), as(当……时), while(在……期间), as soon as(一……就……), before(在……之前), after(在……之后), since(自从……以来),not…until(直到……才), until/till(直到……时), once(曾经)。
特殊引导词：
the minute, the moment, the second, every time, the day, the instant(瞬间，顷刻), immediately, directly(不久，立即), no sooner…than(一……就……), hardly…when(刚一……就……), scarcely…when(刚……就……/一……就……), as soon as(一……就……)。
1.when引导的时间状语从句。
《剑桥雅思真题7》Test 3 Passage 1
When we think of intelligent members of the animal kingdom, the creatures that spring immediately to mind are apes and monkeys.
当我们想到动物王国中有智慧的成员时，脑海中立刻浮现的生物是猿猴。
《剑桥雅思真题7》Test 4 Passage 1
What they had failed to reckon with was what happened when the kite was opened.
他们没有想到的是风筝被打开时发生了什么事。
《剑桥雅思真题8》Test 2 Passage 1
Consequently, when pouring molten glass onto the molten tin, the underside of the glass would also be perfectly flat.
因此，当把熔融的玻璃倒到熔融的锡上时，玻璃的底部也会非常平整。
《剑桥雅思真题12》Test 2 Passage 2
When he came to write the National Geographic magazine article that broke the story to the world in April 1913, he knew he had to produce a big idea.
1913年4月，当他为《国家地理》杂志撰写一篇文章，将这个故事公之于众时，他知道自己必须提出一个伟大的想法。
2.while引导的时间状语从句。
while引导的时间状语从句的谓语动词一般是持续性的，表示“在一段时间内”或“在……时”。
《剑桥雅思真题7》Test 1 Passage 3
In the second part, they listen to baroque music (Bach, Corelli, Handel)while the teacher reads the text in a normal speaking voice.
在第二部分，他们听巴罗克音乐(巴赫、科雷利、韩德尔)，老师用正常的声音朗读课文。
《剑桥雅思真题9》Test 2 Passage 3
Observation of iconoclasts shows that they embrace novelty while most people avoid things that are different.
对传统叛逆者的观察表明，他们乐于接受新鲜事物，而大多数人则回避不同的事物。
3.as引导的时间状语从句。
as引导的时间状语从句具有同时发生的性质，表示“一边……一边……”“当……的时候”“随着……”
《剑桥雅思真题7》Test 4 Passage 1
The idea was that as one end of the column rose, the base would roll across the ground on a trolley.
这个想法是，当柱子的一端升起时，底座就会在手推车上滚过地面。
《剑桥雅思真题8》Test 1 Passage 1
As the Roman Empire expanded northward, it organized its activity chart for the most part around the solar year.
随着罗马帝国向北扩张，它在太阳年前后组织了大部分活动图。
《剑桥雅思真题10》Test 1 Passage 2
In the last 20 years, as internal frontiers have been abolished, the EU has moved from a‘stock' economy to a ‘flow' economy.
在过去的20年里，随着内部边界的废除，欧盟已经从股份制经济转向流动经济。
《剑桥雅思真题11》Test 1 Passage 2
As the wheel rotates, the gondolas are kept in the upright position by a simple gearing system.
当车轮旋转时，通过一个简单的传动系统使平底船保持直立状态。
4.since引导的时间状语从句。
(1)since引导时间状语从句时，其主句通常用完成时或完成进行时，从句用过去时。
《剑桥雅思真题6》Test 1 Passage 1
Since the tests were introduced, AIS athletes in all sports have been remarkably successful at staying healthy.
自从引入这项测试以来，所有运动项目的AIS运动员在保持健康方面都取得了显著的成功。
《剑桥雅思真题7》Test 3 Passage 2
A number of techniques developed since the 1950s, however, have placed the study of these subjects on a sounder and more objective footing.
然而，自1950年代以来发展起来的一些技术使对这些主题的研究有了更健全和更客观的基础。
《剑桥雅思真题9》Test 4 Passage 2
This has been seen by many to be the aspect of the self which is most influenced by social elements, since it is made up of social roles and characteristics.
许多人认为这是自我最受社会因素影响的方面，因为它是由社会角色和特征组成的。
(2)“It be +一段时间(long time/ages/years)+since+一般过去时、现在完成时或过去完成时”。
《剑桥雅思真题6》Test 3 Passage 1
Almost unbelievably, it is a mere 100 years since that train arrived and the audience screamed and fled.
几乎令人难以置信的是，距离那辆火车到达，观众们尖叫着逃离，时间仅100年。
5.till/until引导的时间状语从句。
(1)until和till意义相同，肯定形式表示的意思是“做某事直至某时”，动词必须是延续性的。否定形式表达的意思是“直至某时才做某事”，动词为延续性或非延续性都可以。但until可用于句首，而till通常不用于句首。当Not until…在句首时，主句用倒装。
《剑桥雅思真题9》Test B Section 2
Instead, practise your dynamic introduction and conclusion until you can deliver them effectively.
相反，练习你的动态介绍和结论，直到你能有效地传达它们。
《剑桥雅思真题10》Test 2 Passage 1
Tea was relatively expensive until Britain started a direct clipper trade with China in the early 18th century.
茶叶相对来说比较昂贵，直到18世纪初英国与中国开始了直接的快船贸易。
《剑桥雅思真题2》Test A Section 3
Not until 1772 did he come across a book on astronomy.
直到1772年，他才偶然发现一本天文学方面的书。
(2)句式“It was not till/until...that...”是强调结构，所强调的是till/until引导的时间状语。
《剑桥雅思真题3》Test 1 Passage 1
It was not until the eighteenth century that Europe became seriously interested in the possibilities of using the rocket itself as a weapon of war and not just to propel other weapons.
直到18世纪，欧洲才开始认真考虑将火箭本身作为战争武器而不仅仅是将其用于推进其他武器。
《剑桥雅思真题6》Test B Section 2
It was not until 1791 that the great French anatomist Georges Cuvier deduced that the animal was in fact a flying reptile, whose fourth finger supported a wing.
直到1791年，伟大的法国解剖学家乔治·居维叶才推断出这种动物实际上是一种会飞的爬行动物，它的第四根手指支撑着一只翅膀。
《剑桥雅思真题9》Test 4 Passage 1
It was not until the spring of that year that she was introduced to Pierre Curie.
直到那年春天，她才被介绍给皮埃尔·居里。
6.before引导的时间状语从句。
Before用于表示某事在过去、现在或将来发生于另一件之前，意为“还没有来得及……之前”。
《剑桥雅思真题5》Test 3 Passage 2
Before the dams were built, the Nile flowed freely, carrying huge quantities of sediment north from Africa's interior to be deposited on the Nile delta.
在大坝建成之前，尼罗河自由地流淌，从非洲内陆带着大量的泥沙向北流向尼罗河三角洲。
《剑桥雅思真题7》Test 1 Passage 1
Before this was discovered, engineers had already built instruments to exploit the principle.
在此发现之前，工程师们已经建造了仪器来开发这一原理。
《剑桥雅思真题8》Test 1 Passage 1
However, it took 14 months of non-stop production, costing the company ￡100, 000 a month, before the plant produced any usable glass.
然而，在工厂生产出任何可用的玻璃之前，该公司花了14个月的时间不停地生产，每月花费10万英镑。
《剑桥雅思真题13》Test 3 Passage 3
After their final demise, a millennium passed before really large-scale cities appeared once more in South Asia.
在它们最终消亡之后，一千年过去了，真正大规模的城市才再次出现在南亚。
7.no sooner… than和hardly… when/before引导的时间状语从句。
两个短语都有“一……就”“刚刚……就”的意思，有时可以互换。用以要说明一件事紧接着另一件事发生。no sooner… than…，引导时间状语从句，主句用过去完成时，than后面的从句用一般过去时。hardly… when一般主句用过去完成时，从句用一般过去时。
注意：hardly/scarcely/barely和no sooner位于句首时，主句需要部分倒装。
He had no sooner returned than he bought a house.
他一回来就买了一套房子。
No sooner had he arrived than he went away again.
他刚到就又走了。
He had hardly had time to settle down when he sold the house.
他还未安顿下来，就卖掉了那所房子。
Hardly had I finished eating when he came in.
我刚吃完他就进来了。
8.“the+表示时间的瞬间名词”引导下的时间状语从句。
the与instan, moment, minute, second等瞬间时间名词连用，意思为“一……就”。
《剑桥雅思真题7》Test 4 Passage 1
The instant the sail opened into the wind, a huge force was generated and the column was raised to the vertical in a mere 40 seconds.
当帆向风打开的瞬间，产生了巨大的力量，柱子在40秒内被提升到垂直。
9.“the+序数词+time”引导的时间状语从句。
《剑桥雅思真题9》Test B Section 2
The first time your boss suggests that you formally present something to your department or a client, your reaction may be to panic.
当你的老板第一次建议你正式地向你的部门或客户展示某样东西时，你的反应可能是惊慌失措。
