Chinese grammar：When will we use 了 in Chinese?

This is one of the simplest of all Chinese particles, one which you probably encountered in Chapter 1 of your textbook. The mother of all Newbie conundrums: 了.

This isn’t meant to be an exhaustive, comprehensive study of 了, but rather a guide as you embark on your Chinese grammar journey (or need a brushing up)!

Let's study the 4 most basic uses of 了 now.

1. After a verb or adjective, indicating completion

In its most basic incarnation, 了 is usually placed after a verb (or occasionally adjective) to indicate completion of an action, which usually indicates the past tense. Yet there are cases when it is used to indicate the expected completion of an action, in which case it is not necessarily past tense.

Examples

wǒ tīng le zhè shǒu gē
我听了这首歌

I’ve listened to this song

wǒ chī le fàn yǐ hòu yào chū qù
我吃了饭以后要出去

After I’m done eating, I want to go out

Ó, zhè ge wèn tí wǒ dǒng le
哦, 这个问题我懂了

Oh, I understand this problem

xiàn jīn mǎi qì chē gèng guì le
现今买汽车更贵了

Buying a car these days is even more expensive

2. End of sentence, indicating change of circumstance

Beyond signalling the completion of a specific verb, adding 了 to the end of a sentence shows a circumstance has changed, and a new state exists.

Examples

wǒ è le
我饿了

I’m hungry (I wasn’t hungry before, but am now!)

tā zhōng yú lái le
他终于来了

He’s finally arrived

wǒ yǐ qián měi tiān kàn diàn shì, dàn shì xiàn zài máng le
我以前每天看电视， 但是现在忙了

Before I watched TV every day, but I’m too busy now

3. Excessive!

A truly wonderful grammar pattern absolutely worth mastering, 太…了 is a set pattern expressing an excessive amount or extent of an adjective or adverb. Learn this pattern, it will serve you well.

Examples

nǐ duì wǒ tài hǎo le
你对我太好了

You are too good to me

zhè jiàn chèn yī tài guì le!
这件衬衣太贵了!

This shirt is way too expensive!

zhè xiē shù jù tài bù kào pǔ le
这些数据太不靠谱了

This data is not reliable at all

4. Able or unable

Finally, the major usage of 了 isn’t even pronounced le! When preceded by either 得 or 不, it is almost always pronounced “liǎo“. In the case of 不了, it indicates the inability or impossibility of completing the verb preceding it. In the case of 得了, it means to successfully complete or finish the task which preceded it, or the ability to complete it.

Examples

wǒ chī bù liǎo
我吃不了

I’m unable to eat this

wǒ méi zuò wán zuò yè, wǒ qù bù liǎo!
我没做完作业， 我去不了!

I haven’t finished my homework, I can’t go!

wǒ néng bàn dé liǎo
我能办得了

I’ll be able to do it

nǐ chī dé liǎo yī zhěng zhǐ jī ma?
你吃得了一整只鸡吗?

You can eat an entire chicken?

So…Remember this

1) 了 is NOT equivalent of past tense. It indicates the completion of an action or change of status, and can be used in any tense. It is not the English equivalent of the suffix -ed. Don’t confuse 了 with 过.

2) 了 is NOT always pronounced “le”. In cases preceded by either 不 or 得 (or in words meaning “to understand” like 了解), it is usually pronounced “liǎo”.

3) You’ll learn more by watching 10 minutes of FluentU videos than scouring the internet for detailed dissertations of small grammar points. Study accordingly.