During the process when foreign learners study Chinese, the group of words “达到、到达” are often used. Both of them are combined by two same characters just with the opposite order. And they carry the meaning of “success to do something or reach something”. But it is easy to distinguish because the difference is obvious.
“达到” is a verb means “realize”, the objects are usually the abstract things such as certain levels, goals and requirements and so on. What the students who learn Mandarin often hear is 达到目的”. However, “到达” indicates “arrive some places or stages” and the subjects are mostly the specific things expressing places like 到达昆明.
When we try to express to pay attention to something in Chinese, those who study in China should learn the words “当心” and “注意”. The former emphasizes to tell people to concentrate on something, indicating to watch out like 当心身体. Teachers in Chinese language school may tell you that the latter one stresses to attach much importance to something. We can say 注意天气变化.
When you go to school to study Mandarin, the pair of repositions “对” and “对于” is one of the teaching points. Both of them are used to lead the objects of certain actions like 对/对于这件事，我们很不满意. In addition, the common structure for them is mainly “对/对于…来说”, meaning to see things from certain views.
There are three levels of meanings for ” 对”. The first one is “toward” like in the sentence 他对我笑. The second meaning that students who study in China often use is “to treat”, for example, 他对我很客气. We can also use it to introduce the objects to illustrate the relationship between things like 他对这事有意见.
The preposition ” 对于” is easy for those who learn Chinese in China to understand because it indicates the treat relationship between people, things or behaviors, which is similar with the third application of “对”. For instance, 对于这件事，我不太了解.
All of these three groups of words are basic to learn in Chinese language learning. Teachers should explain to students in detail so that the students can understand and put them into use correctly.