了

le

aspectual particle

Common Errors

The aspectual particle 了 is used to mark the occurrence or the completion of an action in the past, present or future. It is also referred to as 了1 to distinguish it from the modal particle 了2.

1. Incorrect position

The learners might place 了1 in the wrong position within serial verb constructions, sentences with separable verbs or complements, or at the end of a sentence confusing it with the modal particle 了2.

*昨天他去了大学看老朋友。/ 昨天他去了大學看老朋友。
昨天他去大学看了老朋友。/ 昨天他去大學看了老朋友。
Yesterday, he went to the university to see an old friend.
(In serial verb constructions, 了1 should be placed after the second verb to indicate completion of the entire event sequence: he went to the university and successfully visited his old friends yesterday.)

*上个星期你们已经见面了。/ 上個星期你們已經見面了。
上个星期你们已经见了面。/ 上個星期你們已經見了面。
You already met last week.
(Even though the incorrect sentence is syntactically acceptable, it does not express the completion of the action. Since 见面 is a separable verb, 了1 should be placed between 见 and 面 to indicate the completion of the action.)

*我看了完这本书。/ 我看了完這本書。
我看完了这本书。/ 我看完了這本書。
I finished reading this book.
(The correct placement of 了1 to indicate the completion of the action is after the result complement 完, not before it.)

*我坐下来了。/ 我坐下來了。
我坐了下来。/ 我坐了下來。
I sat down.
(When 了1 is used with a verb and a direction complement such as 下来/下來, it should be placed before the complement to indicate the completion of the action, not after the whole verb phrase.)

2. Omission error

The learners might forget to use 了1 after an action completed at a specific time in the past or after the first action that should be completed before performing a second action in the future.

*上星期日晚上她们看三个小时电影。/ *上星期日晚上她們看三個小時電影。
上星期日晚上她们看了三个小时电影。/ 上星期日晚上她們看了三個小時電影。
Last Sunday evening, they watched a movie for three hours.
(了1 is needed after 看 to indicate that the action of watching the movie for three hours was completed at a specific time in the past, last Sunday night).

*明天我吃饭就出发。/ *明天我吃飯就出發。
明天我吃了饭就出发。/ 明天我吃了飯就出發。
Tomorrow, I’ll leave as soon as I finish eating.
(了1 after 吃 is required to show that eating must be completed before departing. It clarifies that the second action 出发/出發 happens only after the first action 吃饭/吃飯 is concluded.)

3. Addition
error

Some verbs inherently express a point of completion in their meaning or can be further described by an element such as a complement that frames the action as it is completed. Examples include: 毕业/畢業, 结婚/結婚, 下课/下課, 吃完 or 回去. When these verbs are followed by 以后/以後, they naturally indicate that the first action is completed before the second one takes place. Because completion is already implied, the aspectual particle 了1 is not strictly necessary, and it can be either included or omitted in the sentence.

Learners might mistakenly include 了1 in negative sentences where it must be omitted.

4. 了1 with inappropriate verbs

The aspectual particle 了1 only pairs with actions that can be completed. For this reason, it is commonly used with verbs describing actions, which generally should be followed by complements or objects preceded by a modifier.

*我吃了苹果。/ 我吃了蘋果。
我吃了一个苹果。/ 我吃了一個蘋果。
I ate an apple.
(Even though the incorrect sentence is syntactically acceptable, it is perceived as incomplete because there is no modifier before the object or a complement after the verb to specify the action.)

*客人等了。/ 客人等了。
客人等了一会儿。/ 客人等了一會兒。
The guests waited for a while.
(Even though the incorrect sentence is syntactically acceptable, the sentence feels incomplete because 等了 does not provide additional detail about how long the waiting lasted or what exactly was being waited for.)

Some verbs only indicate the occurrence of an event without emphasizing the completion of the action, such as 丢, 开始/開始, 结束/結束, 告别/告別, 进/進, 去, 离开/離開, 发生/發生, 发现/發現 or 出现/出現. These verbs can be followed by 了1 and they can have simple objects without modifier.

Except for these cases, the object of a verb followed by 了1 must be preceded by a modifier; otherwise, the sentence could be perceived as incomplete. In this case, the sentence should be modified as follows:

• Adding the modal particle 了2 at the end of sentence. However, in short sentences with an object without modifiers, it is preferred to use only one 了 that conveys the completion of the action and the emergence of a new situation;
• Continuing the sentence by repeating the same verb or adding more objects;
• Continuing the sentence with another clause introduced by 就 or 才.

了1 is generally not used with modal verbs because they express possibility, ability, intention, obligation or willingness rather than completed actions. It is usually not used with verbs describing mental states like 知道 or relational states like 是.

However, verbs describing a state, such as 认识/認識, 相信, 了解/瞭解, 熟悉, 忽视/忽視 or 误解/誤解, do not have a point of completion, therefore they cannot be followed by 了1. The only possibility of using 了1 with these verbs is if they are further described by an element which frames the action as it is completed. This further description can be an object with a modifier composed of a numeral and a measure word.

Some verbs such as 相信, 忽视/忽視 or 误解/誤解, can be followed by 了1 even if they have a simple object without modifiers after it.

Some verbs describing lasting emotions, such as 爱/愛, can be followed by 了1 only if they are followed by a verbal measure word or a complement, which changes the meaning, for example into 爱上/愛上.

了1 is usually not used with verbs describing relational states, such as 是, 像 or 属于/屬於, but it can be used with 有 or 成为/成爲.

In direct quotations, 了1 cannot be used after verbs reporting what people say or think, such as 说/說, 回答, 问/問 or 讲/講. However, if they are followed by an object with a modifier, 了1 can be used to introduce direct quotations.

了1 is not used with some verbs that can take a verb phrase or a clause as their object. These verbs include: 决定/決定, 知道, 看见/看見, 宣布/宣佈, 发现/發現, 听说/聽說, etc.

The modal particle 了2 can be added at the end of these sentences to indicate that the event expressed by the verb phrase or clause is already occurred.

If the speaker wants to emphasize these actions, 了1 can be used, but it is usually followed by a second sentence preceded by a comma.

Also the verbs like 觉得/覺得, 认为/認爲, 希望, 需要 and 作为/作爲 that can take a verb phrase or a clause as their object, are not followed by 了1.

Causative verbs like 让/讓 or 请/請, that induce action in someone or something else and create pivotal constructions, are usually not followed by 了1. Pivotal constructions are sentences with two verbs, where the object of the first verb also functions as the subject of the second verb. These sentences typically start with a main subject, followed by the first verb (often a verb of asking, ordering or causing) then its object, which serves as the “pivot” linking the two verbs. The second verb may also take its own object, creating a structure where one action influences or leads to another.

The second verb in the chain may take 了1 to emphasize that the desired action has already taken place.

He invited his girlfriend to have a meal.
他请女朋友吃一顿饭。/ 他請女朋友吃一頓飯。
(Without 了1, the invitation is being made, but the action of having the meal has not necessarily occurred yet.)
他请女朋友吃了一顿饭。/ 他請女朋友吃了一頓飯。
(With 了1, the meal has already happened.)

She let me go to her house.
她让我去她家。/ 她讓我去她家。
(Without 了1, the request is being made, but the action of going has not necessarily occurred yet.)
她让我去了她家。 / 她讓我去了她家。
(With 了1, the action of going has already happened.)

Additionally, disyllabic dative verbs with 给/給 cannot be followed by 了1.

5. 了1 in serial verb constructions

Serial verb constructions typically consist of a sentence with two verbs that share the same subject. These constructions can express reason, purpose, sequential actions or manner of performing an action. If both actions are completed, 了1 is placed after the second verb.

*昨天他去了大学看老朋友。/ 昨天他去了大學看老朋友。
昨天他去大学看了老朋友。/ 昨天他去大學看了老朋友。
Yesterday, he went to the university and saw an old friend.
(了1 should be placed after the second verb 看 to indicate completion of the entire event sequence: he went to the university and successfully visited his old friends yesterday.)

The sentence 昨天他去了大学看老朋友/昨天他去了大學看老朋友 seems incomplete. It can become acceptable only adding more elements after the sentence such as a clause, or adding a modifier before 大学/大學.

昨天他去了大学看老朋友，还一起去食堂吃饭。/ 昨天他去了大學看老朋友，還一起去食堂吃飯。
Yesterday, he went to the university to see his old friend, and they also went to the cafeteria to have a meal together.

昨天他去了清华大学看老朋友。/ 昨天他去了清華大學看老朋友。
Yesterday, he went to Tsinghua University to see an old friend.

6. Confusion between the aspectual particle 了1 and the modal particle 了2

These particles share the same character, but they differ in position, meaning, and usage.

Position: In most cases, if 了 is not at the end of the sentence and comes right after a verb describing an action, often followed by a modified object or a complement, it functions as the aspectual particle 了1. If 了 is at the end of a sentence containing a verb (describing an action or a state), an adjectival predicate or a modal verb, but not placed directly after them, it functions as the modal particle 了2. If 了 comes right after a verb and is also at the end of the sentence, it could be either particle and its meaning depends on the context.

Meaning: The aspectual particle 了1 can indicate the occurrence or completion of an action or event, clarify the sequence of actions and events in a sentence, and mark a major event among others that are less important. The modal particle 了2 mainly conveys the meaning of a change of state.

Usage: The choice between these particles often depends on the context and the speaker’s intention. If the speaker wants to emphasize the completion of an action, he should use the aspectual particle 了1 right after the verb. If the speaker wants to report a new situation, he should use the modal particle 了2 at the end of the sentence.

*我想了去中国学习。/ 我想了去中國學習。
我想去中国学习了。/ 我想去中國學習了。
I’ve decided to go to China to study.
(了1 cannot be used after 想 because it is a modal verb expressing willingness rather than a completed action. 了2 can be used in this sentence to emphasize a change in the speaker’s state of mind or decision, indicating that he has now made up his mind to go study in China.)

老师都说汉语词典很有用，所以我就买一本汉语词典了。/ 老師都說漢語詞典很有用，所以我就買一本漢語詞典了。
The teachers all said that the Chinese dictionary is very useful, so I decided to buy one (and now I have it).
(In this sentence, 了2 at the end emphasizes a change of mind or decision, the speaker may not have planned to buy the dictionary before but has now decided to do so.)
老师都说汉语词典很有用，所以我就买了一本汉语词典。/ 老師都說漢語詞典很有用，所以我就買了一本漢語詞典。
The teachers all said that the Chinese dictionary is very useful, so I bought one.
(In this sentence, 了1 simply marks the completion of the action of buying the dictionary without implying any shift in mindset or state.)

However, sometimes both particles can be used in the same sentence to emphasize the completion of the action and the emergence of a new situation. If there is a time-measure complement and a verb indicating duration, the presence of the modal particle 了2 indicates that a certain portion of the action is complete but that the action is still continuing.

她学了一年汉语。/ 她學了一年漢語。
She studied Chinese for one year.
(Without additional context, this sentence indicates the completed action of studying for one year, without confirming if she is still learning.)
她学了一年汉语了。/ 她學了一年漢語了。
She has been learning Chinese for a year now.
(This sentence implies that she has been learning Chinese for a year and probably the action has continued up to the present and is still ongoing.)

他吃了四个苹果。/ 他吃了四個蘋果。
He ate four apples.
(This sentence focuses on the completed action of eating four apples.)
他吃了四个苹果了。/ 他吃了四個蘋果了。
He has already eaten four apples (and might eat more).
(This sentence implies that he has finished eating four apples and may continue eating.)

If the verb does not indicate duration, the modal particle 了2 emphasizes the relevance of the action in the present or serves as confirmation that an action has been completed.

A: 爷爷死了多久？/ 爺爺死了多久？
How long has it been since Grandpa passed away?
B: 爷爷死了三年。/ 爺爺死了三年。
Grandpa passed away three years ago.
A: 你们为什么把爷爷的房子卖掉？/ 你們爲什麼把爺爺的房子賣掉？
Why did you sell Grandpa’s flat?
B: 爷爷死了三年了 / 爺爺死了三年了 ……
It’s been three years since Grandpa passed away… (so it is time to sell the flat)
(In the last response, 了2 at the end of the sentence adds a layer of emphasis on the passing of time and the state of things now, implying the action of selling the flat may be related to the new state after the death.)

7. Confusion between the aspectual particles 了1 and 过/過

The aspectual particle 了1 is used to indicate an action that has occurred or has been completed in the past, usually in a specified time, but also in the present or future. The aspectual particle 过/過 is used to indicate that the action of the verb is something that has been experienced in the past.

她去了中国两次。/ 她去了中國兩次。
She went to China twice.
(了 only indicates that the event of going to China was completed twice.)

她去过中国两次。/ 她去過中國兩次。
She has been to China twice.
(过/過 focuses on it having been experienced going to China twice in the past.)

她在这个银行工作了五年。/ 她在這個銀行工作了五年。
She worked in this bank for five years.
(This statement emphasizes that the act of working in this bank for five years was successfully concluded.)

她在这个银行工作过五年。/ 她在這個銀行工作過五年。
She worked in this bank for five years.
(This could be a statement emphasizing that the act of working in this bank for five years gave her experience and knowledge about the working conditions there.)

The modal particle 了2 can also appear together with the aspectual particles 过/過 or 了1 in a sentence. The presence of both the modal and the aspectual particle 了 in a sentence emphasizes the completion of the action or its relevance to the present. The presence of the modal particle 了2 in a sentence with the aspectual particle 过/過 only adds emphasis to that experience.

A: 她去了中国没有？/ 她去了中國沒有？
Did she go to China?
B: 她去了中国两次了。/ 她去了中國兩次了。
She went to China twice.
(She is probably still in China now. This reply could be a statement emphasizing that the action of going to China has happened twice and might still have ongoing relevance.)

A: 她从来没去过中国吗？/ 她從來沒去過中國嗎？
Has she ever been to China?
B: 她去过中国两次了。/ 她去過中國兩次了。
She has been to China twice.
(Maybe she is not in China now. This reply could be a statement refuting the claim that she has never been to China, regardless of whether she is in China right now.)

8. Confusion between the aspectual particle 了1 and the 是……的 structure

Learners might confuse the aspectual particle 了1 and the 是……的 structure, because both are used to talk about past actions or events. While 了1 indicates that an action or event has been completed, the 是……的 structure emphasizes certain details regarding the action, such as time, manner or place. For this reason, it is generally used to answer or ask questions about these details.

The 是……的 structure is specifically suited for providing clear and specific information about past events in sentences that can be translated as passive in English. Such sentences focus on the circumstances of the action and do not emphasize the completion of the action, so 了1 cannot be used.

9. Confusion between the aspectual particles 了1 and 着/著

In sentences describing the existence or presence of something or someone in a place or location, the use of 着/著 and 了1 has a different semantic focus.

桌子上放着一本书。/ 桌子上放著一本書。
There is a book on the table.
(The focus is on the persistent state resulting from the action of the verb “to place”.)

桌子上放了一本书。/ 桌子上放了一本書。
A book has been placed on the table.
(The focus is on the completion of the action of placing something somewhere.)

When expressing a sequence of actions, the learners might confuse 着/著 and 了1. The aspectual particle 了1 can be used to clarify the sequence of actions and events. It indicates that a second action occurs after the first one is completed. However, the actions are not necessarily realized in the past, they may also be realized in the future.

The aspectual particle 着/著 is used when two events occur at the same time, but there is a main event and a background event which describes the manner or state of the second action, and the first action does not need to be completed before the second.

10. Contextually inappropriate usage

Learners might mistakenly add or omit 了1 when it should be used to mark a major event or action among others less important ones. Only the major action or event should be followed by 了1; for the other actions, 了1 is omitted.

L1 Interferences Errors

Learners may assume that the Chinese 了1 is equivalent to the past simple tense in English, leading them to incorrectly use 了1 for any past event or action. However, not all past events or actions in Chinese require 了1. For example, 了1 cannot be used for actions that were performed regularly.

Last year, he was late every day.
*去年他每天都迟到了。/ *去年他每天都遲到了。
去年他每天都迟到。/ 去年他每天都遲到。

When I was in university, I often went to the library to study Chinese.
*我上大学的时候，常常去图书馆学了汉语。/ 我上大學的時候，常常去圖書館學了漢語。
我上大学的时候，常常去图书馆学汉语。/ 我上大學的時候，常常去圖書館學漢語。