いけない
いけない · ikenai · JLPT N3 · expression
bad
🚫 いけない = いける (can go) + ない (not): it can't go, so it's no good
いける is the potential form of 行く (to go), so いけない literally means it cannot go. Japanese uses it for anything off-limits or wrong, as in 食べてはいけない (you must not eat). A plain verbal hook: can't go means not allowed.