Let's Get Familiar With China's Sexiest Word, 了

了 has the power to CHANGE EVERYTHING for your Mandarin game (this is a pun).   Up until this point, you may have a limited knowledge of how 了actually works.  I want you to stop and reflect on your knowledge of 了 so far.  Please take the time to answer these questions.  ACTUALLY DO THIS!

How do you currently understand 了?

What are some situations that you shouldn't use 了 in?

What are some situations that you should use 了 in?

DID YOU ANSWER THEM?

So let's check in on how correct your understandings were. 
Here we are going to learn some meanings of 了 with LOTS of example sentences. 😎
I'll save you my poetic waxing and just hop right into it. 

1. Completion with 了:

• Indicates that an action is completed.

• Emphasize that you completed doing something for a period of time

• Appears with verb complements

2. 了 to mark change of state:

• Expresses “it is no longer the case that … anymore”

• Expresses “it is now the case that…”

3. 了 in set structures. These are best seen as fixed vocabulary items.

1. Completion With 了

This is the 了 we are most familiar with up to this point, so this will mostly be a quick review of how this can be used.  Here are the big points:

1) This use of 了 can express English past tense when we lack context and time words to make the tense clear (example 1), or when we want to emphasize the event (examples 2):

Example 1：	Example 2：
Nǐ chī le ma？ A: 你吃了吗？	Nǐ zuótiān qù le nǎlǐ？ A: 你昨天去了哪里？
Wǒ yǐjīng chī le. B: 我已经吃了。	Wǒ qù le péngyou jiā. B: 我去了朋友的家。

2) It is used to express that you completed doing something for a period of time (kind of like the word "for"), that we learned from "Expressing Duration with 多久".

Example 1：	Example 2：
nǐ jīntiān xué le duō jiǔ？ A:  你今天学了多久？ （You, today, studied for how long?）	Nǐ qù shànghǎi de shíhòu, zuò huǒchē zuò le jǐ gè xiǎoshí? A：你去上海的时候，坐火车坐了几个小时？
wǒ xué le sānshí fēnzhōng. B:  我学了三十分钟。	wǒ zhǐ zuò le sì ge xiǎoshí！ B：我只坐了四个小时！

3) It is placed after verb complements, almost always (unless the complement is negative)

Example 1：	Example 2：
Nǐ shōushí hǎo xínglǐ le ma? A：你收拾好行李了吗？	Nǐ zài měiguó kàn dàole shénme? A：你在美国看到了什么？
Wǒ shōushí hǎole.  B：我收拾好了。	Wǒ zài měiguó kàn dàole hěnduō piàoliang de fēngjǐng. B：我在美国看到了很多漂亮的风景。

Example when complement is negative:

   Yīnwèi wǒmen méiyǒu mǎi dào jī piào, suǒyǐ wǒmen zuòle gāotiě.
✅ 因为我们没有买到机票，所以我们坐了高铁。

Wǒmen méiyǒu mǎi dàole jī piào.
❌ 我们没有买到了机票。

Wǒ zuótiān méiyǒu chī dào nán péngyǒu zuò de cài.
✅ 我昨天没有吃到男朋友做的菜。

Wǒ zuótiān méiyǒu chī dàole nán péngyǒu zuò de cài.
❌ 我昨天没有吃到了男朋友做的菜。

2. Change of State

This usage is the reason 了 is so sexy.  Brace yourself. 

So you have probably seen some sentences where 了 was placed at the end of a sentence or a clause and been kind of like, "well what is 了 actually doing here? The verb is way back there!"  You are about to understand, and holy cow is it cool! 

First, some examples for context:

Wǒ huì shuō zhōngwénle! ——> I can speak Chinese now!! 我会说中文了！	——> implies I could not speak before. Expresses “it is now the case that…”
Wǒ bù ài nǐle! Wǒmen fēnshǒu ba! ——> I don't love you anymore! Let's break up! 我不爱你了！我们分手吧！	——>implies I loved you before. Expresses “it is no longer the case that … anymore”
Tiānqì hǎole yǐhòu, wǒmen qù páshān kàn fēngjǐng ba! ——> After the weather has gotten better, then let's go hiking (and) check out some scenery! 天气好了以后，我们去爬山看风景吧！	——>implies the weather is bad now.
When 了 appears at the end of a sentence or phrase, it is saying that the entire phrase before that is a NEW THING! It is saying that the sentence is a new state we have entered; this new context is the new state that [my Chinese ability, or my love for you, or the weather, or her having/having not been to China] is in now! In fact, 了 can often be translated into "now" or "anymore", as in examples 1 and 2.  In each of these sentences, the 了 is taking the entire sentence and saying that things changed from a previous state to this state, and this implies a lot about the context. Looking at the last sentence, it is the same fundamental idea, except that we are using these concepts to express a condition that must be met by adding in the 以后.  It's like saying, "after the situation has become this, then ...."   Read over that a couple of times and try to parse it out.  If it isn't connecting right now, just focus on the first 2 sentences.  =)

SO FREAKING COOOOL!!!!

3. 了 in Set Structures

The most basic use of the 了 particle is in specific set structures. We think that the easiest way for learners to understand these is as set vocabulary items that just are, rather than trying to do any deeper analysis. There are endless examples of these words / patterns, but the most common include:

太 [adjective/special verb] 了	Tā shuō de tài kuàile. ——> he spoke too fast. 他说得太快了。
[adjective] 死了	Zhège xīngqī lěng sǐle. ——> (I) freeze to death this week. 这个星期冷死了。

All of these set patterns can be used to intensify or strengthen the adjective used. That is, these 了 grammar structures emphasize the adjective used in them. The “太 [adjective] 了” structure is also used to express an excess of something. And the  [adjective] 死了 structure is generally used with negative adjectives.

Notice how the English translations of these structures can vary massively. In language learning, it's always important to remember that grammatical patterns rarely match up exactly with those in another language. In other words, translations of the same structure will often be different.

Because of that, we think it's better to focus on understanding the function of a structure rather than any set translations or meanings for it.