write + if + it'd be good to do
kakeba ii
it'd be good to do; you can just do — a general, low-stakes recommendation
meaning: it'd be good to write
分からなかったら、先生に聞けばいいじゃん。
wakaranakattara, sensei ni kikeba ii jan.
If you don't get it, it'd be good to ask the teacher. casual
混んでいるなら、少し待てばいいよ。
konde iru nara, sukoshi mateba ii yo.
If it's crowded, it'd be good to wait a bit. neutral