

The word “了” can be used in several situations. This is the second 了 grammar point. If you are not familiar with the first 了, which can be used for expressing a completed action, check out Grammar: 了 le for Completion, the article and infographic. Today, we are going to introduce another 了 le grammar. Using 了 le to express the changing of the state, or a new situation that just happened.
了 can be used to describe a new situation that just happened. In other words when something has just changed the state of the situation. You place 了 le at the end of the sentence.
The sentence structure of this grammar is pretty simple:
Describe the new situation + 了.
The subject can be omitted sometimes.
Let’s see some examples below.
It was not snowing. A new situation just happened. It is snowing now.
Someone is trying to teach you something new. Initially you were confused, or were still trying to learn it, but finally you got it. Then you can say 懂了!
It is also a common classroom expression when the teacher asks if you understand what they just taught; they may ask 懂不懂? You can say 懂了 if you have figured it out.
You can use this sentence if the waiter comes by and wants to check if you are done eating and he needs to clean the table for you. You can say 我们不吃了 or you also can say 我们吃饱了, which means we are full now. (This also implies the change of state. We were hungry, but we are full now!)
分手 literally means “separate” “hands.” The hands were holding each other, but a new situation happened.
If it was the other way around, and you two were not boyfriend and girlfriend, but you recently just changed your relationship state, then you can say 我们在一起了. 一起 yì qǐ means together. Place 了 at the end of the sentence to express the change of the state.
When asking if the state has just changed, the sentence structure will look like this:
The statement sentence + 了 + question particle.