了 (le): Completed Actions in Chinese
了
了 after a verb marks a completed action, not past tense. It normally does not appear with future time words for one-off future events, and it is not used for habitual or ongoing states.
Published July 4, 2026
Reviewed July 4, 2026
01 / PATTERN
See the Structure
MODEL
Subject + Verb + 了 + Object
Read the structure
了 after a verb marks a completed action, not past tense. It normally does not appear with future time words for one-off future events, and it is not used for habitual or ongoing states. Keep the model Subject + Verb + 了 + Object visible while you compare each sentence.
我昨天去了北京。
I went to Beijing yesterday.
Choose the right context
An action is finished and you want to say it happened: 我昨天去了北京。 The object carries a number or amount: 他买了三本书。 One action finishes before another starts — even in the future: 我吃了饭再走。
他买了三本书。
He bought three books.
Respect the boundary
Simple future plans: 我明天去北京。The time word 明天 already carries the meaning. Habitual actions with 每天 / 常常: routines never take verb-了 — 我每天吃早饭。 States and feelings such as 是, 在, 喜欢, 想: 我喜欢这本书, never 我喜欢了这本书。 After 没(有): 没 already negates a completed action, so the 了 drops — 我没去北京。
我明天去了北京。
(I will went to Beijing tomorrow.)
Repair the pattern
了 with a future time word: 了 says the action is complete, but 明天 says the trip has not happened yet. The two signals clash, so a simple future plan drops 了 entirely. 了 on a habitual action: 每天 describes a routine, not one finished event. Habits and repeated actions keep a bare verb, even when they happened in the past.
我明天去北京。
Use the repaired structure without changing the intended meaning.
02 / MAP
Read the Sentence
Read from left to right and notice the job performed by each part. The labels describe this example; they are not a rule that every Chinese sentence must copy.
我昨天去了北京。
I went to Beijing yesterday.
我
Subject
This part occupies the Subject position in the model pattern.
昨天
Verb
This part occupies the Verb position in the model pattern.
去了
了
This part occupies the 了 position in the model pattern.
北京
Object
This part occupies the Object position in the model pattern.
03 / EXAMPLES
Examples You Can Reuse
Keep the structure stable while changing the people, objects, times, or conditions. Pinyin is shown as reading support; use the Chinese sentence and translation to confirm the grammar relationship.
我昨天去了北京。
I went to Beijing yesterday.
他买了三本书。
He bought three books.
我吃了饭再走。
I'll leave after eating.
我没去北京。
I didn't go to Beijing.
04 / LIMITS
When to Use It — and When Not To
Use it when
- An action is finished and you want to say it happened: 我昨天去了北京。
- The object carries a number or amount: 他买了三本书。
- One action finishes before another starts — even in the future: 我吃了饭再走。
Do not use it when
- Simple future plans: 我明天去北京。The time word 明天 already carries the meaning.
- Habitual actions with 每天 / 常常: routines never take verb-了 — 我每天吃早饭。
- States and feelings such as 是, 在, 喜欢, 想: 我喜欢这本书, never 我喜欢了这本书。
- After 没(有): 没 already negates a completed action, so the 了 drops — 我没去北京。
05 / REPAIR
Compare Right and Wrong
Compare the smallest meaningful change. Each explanation identifies a placement, scope, form, or clause relationship instead of treating the whole sentence as one undifferentiated mistake.
我明天去了北京。
我明天去北京。
了 with a future time word
了 says the action is complete, but 明天 says the trip has not happened yet. The two signals clash, so a simple future plan drops 了 entirely.
我每天吃了早饭。
我每天吃早饭。
了 on a habitual action
每天 describes a routine, not one finished event. Habits and repeated actions keep a bare verb, even when they happened in the past.
我明天去了北京。
了 marks completion; drop it with 明天 for a simple future plan.
我每天吃了早饭。
Habitual actions don't take 了.
我喜欢了这本书。
喜欢 is a state, not an action that completes. States keep a bare verb: 我喜欢这本书。
我没吃了早饭。
没 already negates completion, so 了 must drop: 我没吃早饭。
06 / PRACTICE
Practice the Grammar Point
Complete three short tasks in order: judge the pattern, repair a common error, and build the sentence. Feedback is fixed and reviewed, so these activities do not use a checker allowance.
1. Judge the sentence
2. Choose the correction
3. Build the sentence
Build a complete sentence with 了.
07 / APPLY
Apply It in Your Sentence
Write one original sentence with 了. Your draft moves to the checker through this browser session, selects this grammar point as the first review focus, and waits for you to submit.
08 / QUESTIONS
了 (le): Completed Actions Questions
Does 了 mean past tense?
No. 了 marks a completed action, not tense. Past habits take no 了 (我每天吃早饭), and 了 can appear in future sequences: 我吃了饭再走 — I'll leave after I eat.
Where does 了 go in the sentence?
For completion, right after the verb: 买了三本书. A different 了 at the end of a sentence signals a new situation (下雨了) — that is a separate use with its own rules.
Can I use 没 and 了 together?
Not for simple negation. 没(有) already says the action didn't complete, so the 了 drops: 我没去北京, never 我没去了北京.
09 / SOURCES
Sources and Review Notes
These references support different parts of the lesson. GF0025-2021 supports level placement only; professional grammar works support the explanation, limits, examples, and cross-checks. Their inclusion does not imply endorsement.
Modern Mandarin Chinese Grammar: A Practical Guide, 3rd ed.
Ross, Ma, Chen, He and Yeh · Routledge · 2024
Locator: Construction index and function chapters relevant to 了
Supports the learner-facing account of where 了 appears and what communicative job it performs.
Official sourceChinese: A Comprehensive Grammar, 2nd ed.
Yip and Rimmington · Routledge · 2016
Locator: Relevant sentence and clause chapters for 了
Cross-checks the Subject + Verb + 了 + Object pattern, clause relationship, and limits represented by the reviewed examples.
Official sourceChinese Proficiency Grading Standards for International Chinese Language Education (GF0025-2021)
Ministry of Education and State Language Commission · Ministry of Education of the PRC · 2021
Locator: Appendix A, Level 1 grammar inventory
Supports directory placement at HSK 1; it does not independently prove usage rules.
Official source10 / CONTINUE
Continue with a Connected Rule
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过The Particle 过 (guò)
Compare a completed event with an experience at any past time.
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一…就The 一...就... Structure
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X就是了X就是了 Settled Remedy
Contrast sentence-final completion with a conversational remedy proposing what to do next.
Easy to confuse
要、快要、就要……了Imminent Events with 要、快要、就要……了
Compare completed or changed situations with events that are only about to occur.
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