GRAMMAR IN PRACTICE
了 vs 过: events, experience and changes with practice
Use verb + 了 to present an event as a bounded whole, and verb + 过 to focus on prior experience. Sentence-final 了 can signal a new situation. Choose the meaning you need before choosing the particle; neither particle simply replaces an English tense ending.
Compare the question being answered
“What did you do after class?” calls for a particular event: 我买了一本练习册. “Have you ever used this kind of workbook?” asks about experience: 我用过这种练习册. The object can be similar while the speaker’s focus changes.
A date does not mechanically ban 过. For example, 上周我去过那家书店 can be natural when establishing recent experience with that shop. Judge the context rather than deleting 过 whenever you see a time word.
A changed situation is different from a past event
我不喝咖啡了 reports a change: I no longer drink coffee. It does not mean I failed to drink one particular coffee yesterday. Compare 我昨天没喝咖啡, which denies that past event.
For an ordinary denied event, use 没 + verb without the completed-event 了: 我没买练习册. To deny prior experience, retain 过: 我没用过这种练习册. Sentence-final 了 has other jobs, so “all negative sentences ban 了” is too broad.
Check the whole message
First label your intention: one event, experience or a new state. Then check time, negation and what the listener already knows. If both an experience and its current relevance matter, 过 and sentence-final 了 can occur together; a forced either/or rule will miss that distinction.
Original examples: understand, then adapt
1. 下课以后，我买了一本练习册。
Xiàkè yǐhòu, wǒ mǎi le yì běn liànxícè.
After class, I bought a workbook.
This reports a purchase in a sequence of events.
Compare structure, meaning and other valid expressions
我买过这种练习册。
This shifts the focus to prior experience of buying that kind; it does not by itself report the specific purchase after class.
2. 我用过这种练习册。
Wǒ yòng guo zhè zhǒng liànxícè.
I have used this kind of workbook before.
The focus is experience, not a report of today’s purchase.
Compare structure, meaning and other valid expressions
我今天用了这种练习册。
This reports a use today. It is a different focus from the general experience stated with 过.
3. 我不坐这趟车了。
Wǒ bú zuò zhè tàng chē le.
I am not taking this service anymore / after all.
Sentence-final 了 presents a changed plan or habit; context decides which.
Compare structure, meaning and other valid expressions
我昨天没坐这趟车。
This denies one past trip. It does not itself announce a changed future plan or habit.
4. 我昨天没买面包。
Wǒ zuótiān méi mǎi miànbāo.
I did not buy bread yesterday.
没 denies the particular buying event; no completed-event 了 is needed.
Compare structure, meaning and other valid expressions
我昨天没买了面包。
For the intended simple denial, remove the event 了. Do not generalize this to all uses of sentence-final 了.
5. 我没听过这个故事。
Wǒ méi tīng guo zhège gùshi.
I have never heard this story before.
Keep 过 when denying prior experience.
Compare structure, meaning and other valid expressions
我没听这个故事。
This can deny listening on a particular occasion. It does not explicitly say the speaker has never heard it before.
6. 天冷了。
Tiān lěng le.
It has turned cold.
Sentence-final 了 marks a change of situation; it does not turn 冷 into a past-tense form.
Compare structure, meaning and other valid expressions
天很冷。
This describes the temperature without explicitly presenting a change. Both sentences can be appropriate in different contexts.
Answer first, then check the reasoning
1. You never used this app. Complete: 我没用___这个应用。
Answer and explanation
过: 我没用过这个应用 denies prior experience. 我没用这个应用 could refer to one occasion and does not by itself express “never before”.
2. Does 我不参加了 mean “I did not attend yesterday”?
Answer and explanation
No. It normally changes a plan or an ongoing participation arrangement. For yesterday’s nonattendance, say 我昨天没参加.
3. Is 我上个月去过那个展览 automatically wrong because it includes a month?
Answer and explanation
No. It can establish a relevant prior visit. A time phrase alone does not determine whether the speaker is reporting an event or invoking experience.
4. A learner used to take the bus but now walks. Which expresses the change: 我不坐公交车了 or 我昨天没坐公交车?
Answer and explanation
我不坐公交车了 expresses the changed habit or arrangement. 我昨天没坐公交车 only denies yesterday’s trip and does not establish the new habit.
Change the conditions and make it yours
Write three separate messages: you bought a new dictionary yesterday; you have used that kind of dictionary before; you no longer carry the paper version.
Show one possible response
我昨天买了一本新词典。我以前用过这种词典。我不随身带纸质版了。
Keep the purchase, experience and changed habit separate. Explain what each 了 or 过 contributes instead of calling all three sentences “past tense”.
Sources and verification
References checked:
Take the practice with you
Print for personal study or classroom practice, keeping the source credit. Reference expressions are not the only possible answers. These are not official exam papers or an AI accuracy benchmark.
- Sentence repair lab (PDF) 中文 / English
Five editing cases, meaning-preservation checks and reference answers. Bilingual PDF.
- Six grammar transfer cards (PDF) 中文 / English
Six patterns with contrasts, boundaries, a self-check and a new-context task. Bilingual PDF.