The main way to set the time in Chinese is through time specification (yesterday, next year…).
Anyway, if we need to emphasize, that we have an experience with particular action, we use particle 过 <guo> and place it right behind a verb.
<Wǒ mǎi le qìchē.>
I to buy le a car.
I BOUGHT A CAR. – in a sense that car-buying action was finished.
<Wǒ mǎi guo qìchē.>
I to buy guo a car.
I HAVE BOUGHT A CAR. (I have the experience of buying a car.)
<Tā qù le Zhōngguó.>
He to go le (to) China.
HE WENT TO CHINA.
<Tā qù guo Zhōngguó.>
He to go guo (to) China.
HE HAS BEEN TO CHINA.
Negation: it is a negation in the past, therefore we use 没(有) <méi(yǒu)>, with one important detail – 过 <guo> unlike 了 remains in a sentense..
<Wǒ méi mǎi guo qìchē.>
I not to buy guo a car.
I HAVE (NEVER) BOUGHT A CAR.
<Wǒ méi qù guo Zhōngguó.>
I not to go guo (to) China.
I HAVEN’T BEEN TO CHINA.
<Nǐ yǒu-meiyou kàn guo zhè bù diànyǐng?>
You youmeiyou to see guo this film?
HAVE YOU SEEN THIS FILM?
<Tā yǒu-meiyou gěi nǐ jiǎng guo zhège gùshì?>
He youmeiyou to you to tell guo this story?
HAS HE TOLD YOU THIS STORY?
<Wǒ cónglái méi mǎi guo qìchē.>
I never not to buy guo a car.
I HAVE NEVER BOUGHT A CAR.
<Wǒ cónglái méi zuò guo Zhōngguó fàn.>
I never not to make guo chinese food.
I HAVE NEVER COOKED CHINESE FOOD.