Subject + 很快 + Verb Phrase
The adverb 很快 (hěn kuài) means 'quickly,' 'soon,' or 'very fast' and is used to describe the speed of an action or how soon something happens. It is placed before the verb it modifies. For example, 照片很快在网上走红 means 'the photo quickly went viral online.'
消息传出后,他很快就回复了。
Xiāoxi chuán chū hòu, tā hěn kuài jiù huífù le.
After the news got out, he replied very quickly.
她学东西很快,一个月就能基本交流了。
Tā xué dōngxi hěn kuài, yí ge yuè jiù néng jīběn jiāoliú le.
She learns things very quickly; in one month she could already communicate at a basic level.
天很快就黑了,我们赶紧回家吧。
Tiān hěn kuài jiù hēi le, wǒmen gǎnjǐn huí jiā ba.
It will get dark very soon; let's hurry home.