How you use the particle of 了 in different sentences?

The particle "了" in Chinese has several uses, including indicating completion of an action, change of state, or indicating a new situation. Here are some examples of how it's used in different sentences:

1. Indicating completion of an action:
- 我吃饭了。(Wǒ chīfàn le.) - I have eaten.

2. Indicating change of state:
- 天气变冷了。(Tiānqì biàn lěng le.) - The weather has become cold.

3. Indicating a new situation:
- 他来了。(Tā lái le.) - He has come. (or He is coming.)
- 电话响了。(Diànhuà xiǎng le.) - The phone is ringing.

4. Emphasizing a change or new situation:
- 我们去过北京了。(Wǒmen qù guo Běijīng le.) - We have been to Beijing.
- 他终于明白了。(Tā zhōngyú míngbai le.) - He finally understands.

These are just a few examples of how "了" is used in different contexts. It's a versatile particle with various nuances depending on the context of the sentence.

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1. “了”放在动词后面：
用法： 这种用法通常表示动作的完成、变化的发生、或者表明动作已经进行到某一点。
语法结构： 主语 + 动词 + 了+ 宾语
例句：
我吃了饭，就出去了。 (after eat, I go out.)
他学了一门新语言。 (He learned a new language.)
她看了一个很恐怖的电影。 (She watched a scary movie.)
他们打了一个小时的篮球。 (They played basketball for an hour.)

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2. “了”放在句末：
用法： 这种用法通常用于表示一种变化、动作的完成或者瞬间状态的改变。它还可以用于感叹句或询问句中，表示疑问或强调。
语法结构： 句子 + 了
例句：
他走了。 (He left.)
我们结婚了。 (We got married.)
这个城市变化很大了。 (This city has changed a lot.)
天气变暖和了。 (The weather has become warmer.)
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了（le）
1、V+了+N【eg：我吃了饭/ VN+了【eg：我吃饭了】（表示动作发生）
2、adj+了【eg：天黑了】（表示状态变化完成）
3、V+complement+了【eg：我把咖啡喝完了】（表示动作完成）
4、V+了+动作的次数 eg: 这个星期我上了两次汉语课。（表示发生了的事情的次数）
5、时量补语+了 eg: 我在上海住了三年了。【了用在时量补语结构的句末。表示动作延续。】
6、adj+了 eg: 我妈做菜的手艺太好了。这幅画太漂亮了。（太……了）（可……了）表示程度，可以加感叹。
7、“要……了”要+VN /adj+了，eg：快要下雨了（表示即将要发生。）
summary：
1、Used after an 【adjective or verb 】to show that an action has happened or finished
2、Used in 【fixed construction 】to indicate an exclamation （太…了）or action that is about to take place（要…了）

1、我吃了饭（V+了+N）/我吃饭了（VN+了）（have done）
2、你到学校了吗？/天亮了/天黑了（adj+了）（change）
3、我把咖啡喝完了（V+Complement+了）

初级汉语语法 中国大学MOOC慕课

动态助词“了”结构与例句

丁险峰

1.S + V+ 了 + MW/modifier + O
(1) Ānnī chīle liǎnɡ ɡe pínɡɡuǒ.
安妮 吃了 两个 苹果。
(2) Dàwèi hēle sān pínɡ píjiǔ.
大卫 喝了 三瓶 啤酒。
(3) Mǎdīnɡ mǎile jǐ běn shū.
马丁买了几本 书。
(4) Dàwèihuànle bùshǎo qián.
大卫 换了 不少 钱。
(5) Ānnī mǎile hěnduō dōnɡxi.
安妮 买了 很多 东西。
2.S + V + 了+ 0 +没有?
(1) Ānnī chīle pínɡɡuǒ méiyǒu ?
安妮 吃了 苹果 没有?
(2) Dàwâi hēle píjiǔ méiyǒu ?
大卫 喝了 啤酒 没有?
(3) Mǎdīnɡ mǎle shū méiyǒu?
马丁 买了 书 没有?
(4) Dàwèi huànle qián méiyǒu?
大卫 换了 钱 没有?
(5) Ānnī mǎile dōnɡxi méiyǒu ?
安妮 买了 东西 没有?
3.S+ 没有 + V + 0
(1) Ānnī méiyǒu chī pínɡɡuǒ
安妮 没有 吃 苹果。
(2) Dàwèi méiyǒu hē píjiǔ.
大卫 没有 喝 啤酒。
(3) Mǎdīnɡ méiyǒu mǎ shū.
马丁 没有 买 书。
(4) Dàwèi méiyǒu huàn qián.
大卫 没有 换 钱。
(5) Ānnī méiyǒu mǎi dōnɡxi.
安妮 没有 买 东西。

动态助词“了”情景对话
丁险峰

(安妮在校园里碰到大卫)
安妮:今天的 晚会 有 几个人?
Annie: How many people are there at the party today?

大卫:一共 有十个人。
David: There are ten people in all.

安妮:你 买了 什么 饮料?
Annie: What drinks did you buy?

大卫:我买了啤酒、可乐 和 果汁。
David: I bought beer, cola and juice.

安妮:你 买了 几瓶 啤酒?
Annie: How many bottles of beer have you bought?

大卫:我买了十瓶啤酒。
David: I have bought ten.

安妮:一人 一瓶，够吗?
Annie: One bottle for one person, is that enough?

大卫:女同学 不 喝 啤酒，她们 喝 可乐 和 果汁。
David: Female students don't drink beer. They drink coke and juice.

安妮:那你 请了 几个 男同学?
Annie: How many male classmates have you invited?

大卫:我请了五个 男同学、五个 女同学。男同学 一人两瓶 啤酒，够吗?
David: I have invited five boys and five girls. Two bottles of beer for each boy, is that enough?

安妮:差不多 够了。那我们 几点 开始?
Annie: That will be just about enough. What time shall we start?

大卫:我们八点开始，你快点儿来帮我 准备 准备吧。
David: We are going to start at eight o'clock, you'd better come earlier and help me prepare for the party.

安妮:没问题。
Annie: My pleasure.

大卫:Bye-bye!
David: Bye-bye !

credit: BLCU MOOC

https://www.youtube.com/watch?v=LnkTeKwpP4A ,you can learn from this video.

Change of state with "le" (Also known as: 了2, change-of-state 了, sentence 了 and modal 了)

Used with Adjectives
When an adjective indicates a change to the subject, 了 (le) is placed at the end of the sentence to indicate a change of state.
Structure: Subj. + Adj. + 了
Examples
我 饿 了 。Wǒ è le.I'm hungry.
孩子们 都 累 了 。Háizi men dōu lèi le.The kids are all tired.

Used with Verbs
When following a verb or verb phrase, the 了 (le) indicates a change in an overall situation. For these sentences, sometimes you can translate this 了 (le) as "now."

Structure: Subj. + Verb + 了
Examples
下雨 了 。It wasn't raining, but now it is.Xià yǔ le.It's raining.
宝宝 会 说话 了 。He couldn't before.Bǎobao huì shuōhuà le.The baby can speak now.

Change of Situation in the Negative
When you take the same "change of situation" pattern and put a 不 (bù) before the verb, you're indicating that something already decided has changed. What had once been green-lit is now getting a red light. What was once "on" is now "off." The "change of situation" indicated by 了 (le) is still the same, although the change is often simply mental: it's a change of plans, or a change of intent.

Structure : Subj. + 不 + Verb + 了
Examples
我 不 买 了 。I had previously decided to buy it.Wǒ bù mǎi le.I'm not buying it now.
我 不 回家 吃 晚饭 了 。I had previously decided to go home for dinner.Wǒ bù huí jiā chī wǎnfàn le.I'm not going to go home for dinner tonight.

Aspectual particle "le" (Also known as: 了1, verb 了, completed action 了 and perfective 了)
The particle 了 (le) has a lot of uses. One of the most common is to express the completion of an action.

The simplest way to use 了 (le) is to just put it after a verb. When there's nothing else after the verb, there are no complications!
Structure: Subj. + Verb + 了
Examples
他们 到 了 。Tāmen dào le.They have arrived.
我 买 了 。Wǒ mǎi le.I've bought it.

Putting 了 After a Verb with an Object
Here is where things start to get slightly more complicated. If the verb has an object, 了 (le) can go directly after the verb to indicate completion, but there are a few other conditions that should be met.
When Time is Specified

It's a good idea to specify the time anyway, if you're still getting used to Chinese verbs not indicating tenses by themselves. When you do this, it's generally OK to put the 了 (le) right after the verb and before the object.

Structure :
(1) Subj. + Time + Verb + 了 + Obj.
(2)Time + Subj. + Verb + 了 + Obj.

Examples :
我 今天 吃 了 早饭 。Wǒ jīntiān chī le zǎofàn.This morning I ate breakfast.
她 上个 月 去 了 北京 。Tā shàng gè yuè qù le Běijīng.Last month she went to Beijing.

When the Object's Quantity is Specified
This pattern works if the sentence includes more information about the object, such as how many there are.

Structure: Subj. + Verb + 了 + [Number + Measure Word] + Obj.
Examples :
老师 问 了 五 个 问题 。Lǎoshī wèn le wǔ gè wèntí.The teacher asked five questions.
我 买 了 三 本 书 。Wǒ mǎi le sān běn shū.I bought three .

When 了 Comes After the Object
here's the tricky part. Even when indicating completion, the 了 (le) can sometimes go after the object.

Structure: Subj. + Verb + Obj. + 了
Examples :
上个 月 我 去 台湾 了 。Shàng gè yuè wǒ qù Táiwān le.I went to Taiwan last month.

Putting 了 After Consecutive Actions
So what happens if a whole string of things happened in the past? Do you have to put a 了 (le) after each one, just like we'd put each verb in the past tense in English? Good question! The short answer is that you only need one 了 (le).

structure: Subj. + 来 / 去 + Place + Verb / [Verb Phrase] + 了
Examples:
昨天 她 来 我 家 吃饭 了 。Zuótiān tā lái wǒ jiā chīfàn le.She came to my place and ate dinner yesterday.
我们 上周 去 北京 开会 了 。Wǒmen shàng zhōu qù Běijīng kāihuì le.We went to Beijing and had a meeting there last week.