快 + Verb
快 (kuài) as an adverb before a verb expresses urgency, meaning "hurry up and" or "quickly." It urges someone to perform an action promptly, often used in imperative sentences.
快把门关上,外面太冷了!
Kuài bǎ mén guānshang, wàimiàn tài lěng le!
Hurry and close the door, it's too cold outside!
快看,那边有一只小猫!
Kuài kàn, nàbiān yǒu yì zhī xiǎo māo!
Quick, look, there's a kitten over there!
快告诉我,到底发生了什么事?
Kuài gàosu wǒ, dàodǐ fāshēng le shénme shì?
Hurry up and tell me, what on earth happened?