Express past experience with 过
We already know we can use了le to indicate a completed action, the word 过guò can be used in the similar model，but 过 emphasizes more on the completion, that the action has been done. Let’s see some examples to understand more directly,
|你 吃 饭 了 吗？|
Nǐ chī fàn le ma ？
Have you eaten?
吃 过 了。/吃 了。
Chī guò le. /Chī le.
Yeah, i have.
We can use both 了 and 过 in this case, but with 过 is double assuring that” I have eaten. “
Also 过 has another usage, is when we express “ Have i ever…” type of once in a life experience. The action usually takes place in the past, and is no longer in progress,
Wǒ lái Zhōng guó yǐ hòu ，wǒ qù guò Shànghǎi héQīngdǎo 。
After i came to China, i have been to Shanghai and Qingdao.
我 学 过 中文 一 个 月。
Wǒ xué guò Zhōngwén yí gè yuè.
I learned Chinese for one month before.
Both examples share the similar pattern that the memories are relatively distant. For these kind of situations we use 过.
The question and negative form of 过
The question and negative form will be similar to 了，remember for the answers we need to use 没有 to negate, and the 过 has to be present.
|你 以前 去 过 北京 吗？|
Nǐ yǐqián qù guò Běijīng ma ？
Have you ever been to Beijing?
我 从来 没 去 过。
Wǒ cónglái méi qù guò.
I have never.
我 这 辈子 从来 没 见 过 他。
Wǒ zhè bèizi cónglái méi jiàn guò tā.
I have never seen him in my life.
The complement of frequency 次cì，遍biàn
When we talk about the past experience we would often need the complement of frequency, it is used to indicate the number of times of an action has occurred. This type of complement is formed by a numeral and a verbal classifier, the most common ones are 次 and 遍. They are both to indicate the number of times an act has occurred, but 遍 emphasizes the whole process from the beginning to the end, e.g.
|这 本 书 我 已经 看 过 两 遍 了。|
Zhè běn shū wǒ yǐjīng kàn guò liǎng biàn le.
I have read this book twice.
他 刚才 来 找 过 你 三 次。
Tā gāngcái lái zhǎo guò nǐ sān cì.
He came here to look for you three times just now.
Other verbal classifiers of complement of frequency include“声shēng”,“趟tàng”，“下xià”.
|狗 对 着 我 叫 了 好 几 声。|
Gǒu duì zhe wǒ jiào le hǎo jǐ shēng
The dog barked at me a few times.
你 帮 我 一 下 好 不 好？
Nǐ bāng wǒ yí xià hǎo bù hǎo ？
Can you help me a bit?