介词on表示时间和地点时怎么用？
The preposition 'on' has many uses in English. This page summarizes the uses of 'on' as a preposition and provides examples for each type of use. Important prepositional phrases with 'on' are used to introduce and connect ideas are also listed with appropriate examples.
在英语中，介词on有许多种用法。本章内容对介词on的用法进行了总结，并在每种用法后面附上了例子，另外，介绍了有关on的介词短语，并在定义后加上恰当的例句。
ON – TIME
表示时间
'On' is used as a preposition in time expressions with specific days of the week. Note: 'on the weekend' is used in American English, but 'at the weekend' or 'at weekends' is used in British English.
介词on可以用来和每周里具体的日子连用，来表示时间。注意：on the weekend是美式英语的表达方法，但是英式英语则采用at weekends的用法。
I will see you on Thursday.
我们星期四见面吧。
Peter usually walks to work on Fridays.
皮特总是在周五步行去上班。
ON – PLACES
表示地点
'On' is used flat surfaces both big and small.
on可以表示处于一个或大或小的平面上。
We played footBAll on the field.
我们在操场上踢足球。
The book is on the table over there.
那本书放在桌子上。
'On' is used with planets. The most common usage is 'on earth', but other planets take 'on' as well.
on也可以和星球连用。最常见的表达式on earth，其他的星球也可以和on连用。
You will find a wide variety of life on earth.
地球上的生物种类繁多。
So far, life has not been discovered on Saturn.
目前为止，土星上还没有发现生命的存在。
ON – ONTO
相当于onto
Sometimes 'on' is confused with 'onto'. The preposition 'on' indicates that something is already in the position. 'Onto' indicates a movement from one place onto to surface of some type.
有时候，我们会将on和onto弄混。介词on表示某物已经处于某个位置上。而onto则表示某物从一个地方移动到另一个地方。
The book is on the table. BUT Pete took the book out of his backpack and put it onto the table.
书在桌子上。但是皮特将书从背包里拿出来，放在了桌子上。
Could you move those clothes onto the sofa?
你能把这些衣服放到沙发上吗？
1.ON FOOT
'On foot' is an exception to stating how something moves with 'by'. For example, I went there by boat, by plane or by car. BUT I went there on foot.
on foot是我们用by表示物体移动的一个例外。例如，我乘船/坐飞机/开车去那里。但也可以说，我步行（on foot）去那里。
She left her home and went to town on foot.
她离开家，步行去了镇上。
Jennifer prefers to go shopping on foot.
珍妮弗喜欢步行着去购物。
IMPORTANT PHRASES WITH ON
关于on的重要短语
'On' is used in a number of fixed expressions. These are some of the most common.
on可以用于多种固定表达。下面是一些最常见的。
2.ON BALANCE
'On balance' is used to summarize a situation.
on balance表示对情况进行总结。
On balance, we need to look for new business soon.
总的来说，我们要尽快开展新业务。
We decided that, on balance, it didn't make sense to invest in new product development.
总而言之，我们认为投资于新产品开发没有意义。
3.ON CONDITION (THAT)
'On condition' is used to establish something that must be done in order for something else to happen. 'On condition' can be used in place of 'if'.
on condition表示为了达到某个目的，必须完成某件事，也可以和if互换。
We'll send our daughter to Europe this summer on condition that she gets good grades this semester.
如果女儿这个学期能够取得好成绩，这个夏天我们就送她去欧洲。
On condition that you finish this assignment, I will let you stay out late on Saturday.
如果你能完成这个任务，周六就可以晚点回来。
4.ON ONE'S OWN
'On one's own' refers to action that is done by yourself.
on one’s own表示独自完成某件事。
Time doesn't like to spend much time on his own. He'd rather be with people.
时光不独行，偏爱与人同。
Mary was proud of having paid for her studies on her own.
玛丽为自己能够挣到学费而骄傲。
5.ON THE CONTRARY
'On the contrary' is used to link ideas showing an opposing point of view.
on the contrary表示持相反观点。
On the contrary, I believe that it will be impossible to succeed in this market.
相反，我觉得在市场取得成功是不可能的。
You might think Wilma is a great employee. On the contrary, she isn't very effective.
你可能认为威尔玛是名优秀的员工。刚好相反，她并没有那么好。
6.ON THE OTHER HAND
'On the other hand' is used when showing both the positive and the negative aspects of a situation.
On the other hand表示从积极和消极的方面来看待问题。
We'd think there is a lot of potential to the idea. On the other hand, it's certainly a risky proposition.
我们认为，这个想法具备多种潜能。另一方面，这也确实是一个冒险的提议。
On the other hand, if you don't spend more time on your homework your grades will get worse.
另一方面，如果你不多花点时间在作业上，你的成绩会更差。
7.ON THE WAY
'On the way' indicates that something is physically located on the path to somewhere else.
on the way表示某物位于去某地的路上。
'On the way' can also be used in a figurative sense to indicate that something happened during the course of another action.
on the way也可以比喻在做某事是碰巧发生另一件事。
Let's meet at the school on the way to the park.
我们在去往公园那条路上的学校见面吧。
He happened to meet a lot of great people on the way to his success.
在成功的路上，他偶然遇到了许多优秀的人。
8.ON THE WHOLE
'On the whole' is used to summarize an opinion or discussion.
on the whole用来对意见或讨论进行总结。
On the whole, I think you will agree that our position in the market is excellent.
总的来说，我觉得你会认同我们在市场上的地位。
On the whole, Jack thinks it's a good idea to hire some new employees.
总的来说，杰克觉得雇些新员工是个好主意。
SPECIAL CASE: ON TIME VS IN TIME
特殊用法：on time和in time
'On time' means that you have arrived somewhere at the agreed upon time. 'In time' indicates that you have done something within the appropriate amount of time.
on time表示你在规定的时间里到达了某地。In time表示你在一个恰当的时机里完成了某事。
I arrived at the meeting on time.
我准时出席了会议。
She picked us up at the airport on time.
她准时去机场接我们。
BUT
但是
I finished the report in time for the meeting.
我及时完成了会议的报告。
Janice gave her recommendations in time for us to make an informed decision.
加尼斯及时给她写了推荐信，使我们能够做出知情的决策。
