boil

● (if it's a person boiling something )
to boil water = おゆを わかす ・ お湯を 沸かす
to boil an egg = たまごを ゆでる ・ 卵を ゆでる

● (if it's water, milk )= わく ・ 沸く
the water is boiling = おゆが わいています。 ・ お湯が 沸いています。
(if it's vegetables )= ゆでる