The characters 了and过are often used in the daily life to indicate certain things have finished and they are also the important language points in Chinese language classes. However, there are also some differences between them when being used in the actual situations. In reading process, the students who attend toschool to study in China may feel confused about the application of the two grammar points. As a result, a series of mistakes are made by those beginners of Chinese language learning.

As a matter of fact, 了is placed after verb and adjective for the purpose of indicating the realization of certain act or behavior, emphasizing it has become the reality. For example, the sentence 年纪大了shows that the person has the characteristics of being old. If you say 来了一个人, you probably mean the act has finished or achieved. In the same sense, for the point 了, no matter where the place of the act or state in the whole process, it has no close relationship with the specific time that the act is happening. But it is limited by the other words.

In addition, in the application of indicating to realize something, 了can be used to show the realization in the past, in the future and also at present. For instance, 下了班老师们走出了校门，他现在到了东京and 下了班到我家来一下. When you choose the Chinese school as the place to learn Chinese, teachers would tell you 过is placed after verb and adjective to indicate that such kind of act has been realized in the past. We can say 过is to mean there was certain experience in the past like 我们去过黄山.

If you hear people say我打过毛衣, it means the speaker had the experience of weaving sweater. One point that the learners need to notice is that the application of 了and过is very similar. In some cases, both of them can be used in the same sentence but has great difference in meaning. We can say both 吃了苦头and吃过苦头. Therefore, the students need to pay special attention to the sentences with the two words to improve the accuracy.