A Very Informal Way to Say 'Don't'

I thought maybe I could teach a way of saying 'don't' but the kind of 'don't' you will often read in manga or hear in anime, even in films and on the street among close friends. Anyway, the way of saying this informal 'don't' is taking the verb in it's dictionary form and then adding 'na' at the end, so for example.

食べる　＋　な　=　食べるな = (taberuna) Don't eat!
行く　+　な　=　行くな　=　(ikuna) Don't go!

So take any verb, in it's dictionary form and add 'na' at the end makes it a very informal way to say 'don't.'

So for example, you are cooking a meal and some of the food you have cooked is on the table ready and your friend say's something like '美味しそう'　(Oishisou = that looks delicious) and then goes to taste the food you have cooked you could say '食べるな' (don't eat)

Please be aware this is very informal, and so therefore, is actually a little impolite. This is something you would only use with good friends.