Guo 过/過 is an aspectual particle that always follows the verb in a sentence, and it is used to indicate that an action has been experienced at least once in the past.

Structure
Basic form
Guo 过/過 always follows the verb in a sentence.
In sentences with separable verbs, guo 过/過 is placed directly after the verb and before the object. Separable verbs are a specific group of disyllabic verbs where the two elements can be split because the first element is typically a verb indicating an action, while the second one is often a noun representing the object of that action. Examples of such verbs include chī fàn 吃饭/吃飯 ‘to eat’, jiàn miàn 见面/見面 ‘to meet’ or shuì jiào 睡觉/睡覺 ‘to sleep.
Negation
Since guo 过/過 indicates events that have been experienced in the past, sentences with guo 过/過 are negated using méi 没/沒. For added emphasis, méi yǒu 没有/沒有 can also be used in place of méi 没/沒.
Question
There are three common ways to form a question with guo 过/過 to ask if someone has experienced something before:
- adding méi yǒu 没有/沒有 at the end of the sentence;
- reduplicating the verb and adding méi 没/沒 between them;
- adding the question particle ma 吗/嗎 at the end of the sentence.
In all these three types of interrogative sentences, the aspectual particle guo 过/過 is placed after the verb.
All three types of interrogative sentences mentioned above can be answered affirmatively by using the ‘verb + guo 过/過’ phrase alone, and they can be answered negatively by using the ‘méi yǒu 没(有)/沒(有) + verb + guo 过/過’ phrase.
With adverbs
The adverbs, such as yě 也 ‘too’ and hái 还/還 ‘in addition’, are placed before the verb followed by guo 过/過.
The adverbs cónglái 从来/從來 ‘never’ and hái 还/還 ‘yet’ are frequently paired with guo 过/過 and they are placed before méi(yǒu) 没(有)/沒(有).
With complements
If the action has been experienced, guo 过/過 is placed after the verb and before time-measure complements indicating the duration of the action or before quantitative complements indicating the number of times the action takes place.
Note that the quantitative complement usually precedes the object, but if the object is a place noun, it can also follow the object.
For further information about the position of an object in sentences with quantitative complements and time-measure complements, also check Quantitative complement and Time-measure complement.
In serial verb construction
Serial verb constructions typically consist of a sentence with two or more verbs or verbal constructions that share the same subject. These constructions can express reason, purpose, sequential actions or manner of performing an action. In serial verb constructions, guo 过/過 follows only one verb whose experience is the focus of the statement.
Functions
1. Guo 过/過 expressing past experience
Guo 过/過 often occurs in sentences that convey the idea of having experienced an action at least once in the past, similar to answering the question “Have you ever…?”.
The action may have occurred once or more times, but it cannot be a regular or habitual activity.
The past experience may also refer to a specific time.
Sentences with guo 过/過 are often used to explain a truth or to support a viewpoint.
Note that guo 过/過 is typically used with verbs describing actions that can be repeated and it does not follow verbs whose actions are inherently not repeatable. For example, guo 过/過 does not follow verbs like chūshēng 出生 ‘to be born’ and sǐ 死 ‘to die’ as they are events that occur only once in a person’s life.
However, this also applies to events like bì yè 毕业/畢業 ‘to graduate’ or jié hūn 结婚/結婚 ‘to marry’, which are culturally viewed as once-in-a-lifetime events, but can be used with guo 过/過 in limited contexts and in negative sentences.
Additionally, guo 过/過 cannot be used with verbs that refer to mental states like zhīdào 知道 ‘to know’, rènshi 认识/認識 ‘to know’, jìde 记得/記得 ‘to remember’ or xīwàng 希望 ‘to hope’. Only the verbs jiào 叫 ‘to call’ and xìng 姓 ‘to be surnamed’ can be followed by guo 过/過.
Finally, guo 过/過 can also follow some adjectives when serving as predicates to indicate a state that has existed before.