Soon, Quickly, Fast
Adverb
はやく
きのうはどうして早く学こうに行きましたか。
Why did you come to school early yesterday?
ゆっくり休んで早くよくなってください。
Please get plenty of rest and feel better soon!
早く食べなさい。
Eat quickly.
This is the adverb version of the kanji early It's a little thing you can begin sentences with to say you're doing something early or quickly.
Since you already know the reading of the vocab word 早い, you should be able to read this word as well.