greedy可唔可以加ly?

可以!
greedy+ly=greedily

greedy是(adj.)
形容人的性格
e.g.Tom is a greedy boy.

greedily是(adv.)
形容動作
e.g.Tom eat the cake greedily.

yes

greedy (adjective)
greedily (adverb)

記住如最尾的是 y, 則要先將 y 轉做 i
e.g. happy --> happily

yes! sure

yes. greedily (adv.), greedy (adj.)