When you learn the two words 起来and下来, the Chinese teachers in one-on-one Chinese learning programsmay take 胖起来and瘦下来as examples. However, it might be confusing for you because both起来and下来in the two phrases indicate the meaning of “begin and will continue”. But why, the different words should be applied differently with 胖and瘦. What are the essential differences between them? Let’s take some examples firstly.

After comparing the sentences 刚进腊月，大街小巷就热闹起来了，只有到了夜里，才会安静下来and刚到六点，天就暗下来了，马路两边的路灯纷纷都亮了起来, we can find that the words placed before 起来and下来are different. the words like 亮、热闹and胖before 起来give us the feeling that the things are developing from the low to the high degree, emphasizing the beginning and from static state to the dynamic state.

On the contrary, the words such as暗、安静and瘦before 下来indicating the developing tendency from the high degree to the low, emphasizing from dynamic state to the static. The following comparative words might be helpful for those who study Mandarin online. 发烧and退烧，快and慢，忙and闲，涨and跌，紧张and放松，etc.

Accordingly, we can understand the application by drawing some circles on paper. When using the word 起来, you can express by drawing the circles from small to big gradually because it indicates a certain state develops gradually to a higher degree. On the contrary, you can understand the verbs before下来by drawing the gradually diminishing circles because it implies the state processes to a lower degree.

Now, let’s move our attention back to the beginning of this article. Those who learn Chinese should know we say 胖起来because 胖indicates the tendency to high degree while 瘦in瘦下来shows the diminishing degree of a certain state.