N4 — outside your level filter
write + if
kakeba
if — general, lawlike condition
この道をまっすぐ行けば、駅に出ます。
kono michi o massugu ikeba, eki ni demasu.
If you go straight down this road, you will come out at the station. neutral
安ければ買うんだけどなあ。
yasukereba kau n da kedo naa.
I'd buy it if it were cheap. casual