When English speakers talk about time and place, there are three little words that often come up: in , on , and at . These common words are prepositions that show a relationship between two words in a sentence.
当英语使用者谈论时间和地点时，经常会出现三个小词：in、on 和 at。这些常见单词是介词，显示句子中两个单词之间的关系。
Some prepositions are rather easy for English learners to understand: behind, over, under, next to, etc…
有些介词对于英语学习者来说相当容易理解：behind、over、under、next to等等……
But these little two-letter prepositions seem to create confusion. Here are a few rules to help you understand when to use in , on , and at in a sentence.
但这些两个字母的小介词似乎会造成混乱。这里有一些规则可以帮助您理解何时在句子中使用 in 、 on 和 at 。
For describing time and place, the prepositions in , on , and at go from general to specific .
为了描述时间和地点，介词 in 、 on 和 at 从一般到具体。
Prepositions and Time
介词和时间
Let’s start by looking at how we talk about time. English speakers use in to refer to a general, longer period of time, such as months, years, decades, or centuries. For example, we say “ in April,” “ in 2015” or “ in the 21st century.”
让我们首先看看我们如何谈论时间。说英语的人用 in 来指代一般的、较长的时间段，例如几个月、几年、几十年或几个世纪。例如，我们说“四月”、“2015年”或“21世纪”。
Moving to shorter, more specific periods of time, we use on to talk about particular days, dates, and holidays . You may hear, “I went to work on Monday,” or “Let’s have a picnic on Memorial Day.”
转向更短、更具体的时间段，我们用来谈论特定的日子、日期和假期。您可能会听到“我星期一去上班”或“我们在阵亡将士纪念日去野餐吧”。
For the most specific times, and for holidays without the word “day,” we use at . That means you will hear, “Meet me at midnight,” or “The flowers are in bloom at Easter time.”
对于最具体的时间以及没有“日”一词的假期，我们使用 at 。这意味着您会听到“午夜见我”或“鲜花在复活节盛开”。
Prepositions and Place
介词和地点
When English speakers refer to a place, we use in for the largest or most general places. You can say that “VOA is located in Washington, D.C.” And “for the best food, try the restaurants in Chinatown.”
当说英语的人提到一个地方时，我们用 in 来表示最大或最一般的地方。您可以说“VOA is located in Washington, D.C.” “要想吃到最好的食物，就去唐人街的餐馆吧。”
For more specific places, like certain streets, we use the preposition on . You may know that President Obama lives on Pennsylvania Avenue in Washington, D.C.
对于更具体的地方，例如某些街道，我们使用介词 on 。您可能知道奥巴马总统住在华盛顿特区的宾夕法尼亚大道。
Finally, we get to the most specific places. For exact addresses or intersections, we use the preposition at . If I invited you to visit us here at VOA, I would say, “Come to my office at 330 Independence Avenue.” To be exact, it’s at the corner of Independence and 3 rd Street.”
最后，我们到达最具体的地方。对于确切的地址或交叉点，我们使用介词 at 。如果我邀请你来参观美国之音，我会说：“到我位于独立大道 330 号的办公室来。”准确地说，它在独立街和第三街的拐角处。”
In English, though, there is always an ‘exception to the rule.’ When talking about transportation, things get a little hard to understand. We use on for public vehicles like buses or trains, but also for smaller ones like a bicycle. “I rode there on my bicycle.” However, you ride in a car.
然而，在英语中，总是有“规则的例外”。当谈论交通时，事情就变得有点难以理解。我们将 on 用于公交车或火车等公共交通工具，也用于自行车等小型交通工具。 “我骑自行车去那里。”但是，您乘坐汽车。
Still, it helps to know that English prepositions do have some rules.
尽管如此，了解英语介词确实有一些规则还是有帮助的。
Following the “general to specific” rule should help you most of the time.
遵循“从一般到具体”的规则在大多数情况下应该对您有帮助。
And, I’m Ashley Thompson.
而且，我是阿什利·汤普森。
Now it’s your turn. What helps you to remember the prepositions in English? Do you have any grammar tips you’d like to share? Write to us in the Comments section or on our Facebook page .
现在轮到你了。什么可以帮助你记住英语介词？您有什么语法技巧想要分享吗？请在评论部分或我们的 Facebook 页面上给我们写信。