In visual mode. If you use V (visual mode) to select multiline, then press : prompt will appear >>>:'<,'> So if you need to comment or insert something at first place please do >>>:'<,'>s/^/#/ for example above , I need to comment selected multiline. If you want some change with // , then we have to change delimeter, so >>>:'<,'>s!^!//! Hahaha, Cool , ha?