wow!; oh!; eek!; gee!
yeah!; alright!; hurray!
waah!; boohoo!
suddenly and in a loud voice (e.g. sobbing)
わあ、綺麗な景色だね。
Wow, what a beautiful view!
わあ、プレゼントだ。
Wow, it's a present!
わあ、びっくりした。
Wow, that startled me.