yeah, the negative verb followed by to is one way to do it (a pretty strong way too).
there are so many ways to do it, and they are generally formed in similar ways (if you don't do this, x will happen).
i looked around and found this one which covers しないといけない:
http://www.japanesepod101.com/2007/03/2 ... cards-vii/
My Tokyo Traveblogue - Day 6 also covered it.
http://www.japanesepod101.com/2007/01/2 ... gue-day-6/
Aomori Dialect 2 covers how to do it in tsugaru-ben. the PDF compares it to the standard japanese way:
http://www.japanesepod101.com/2007/03/1 ... ori-ben-2/
Aomori Dialect 3 also covers how to do it tsurgaru-ben. the PDF compares it to the standard way.
http://www.japanesepod101.com/2007/04/2 ... dialect-3/
All Grown Up covers "must not do" using てはいけません
http://www.japanesepod101.com/2006/11/1 ... -grown-up/
Postcards VIII also covers "must not do"
http://www.japanesepod101.com/2007/03/2 ... ards-viii/
Miki's Day in the Life of a student 学生の一日（月曜） 『バイトに行く』 and 学生の一日（月曜）『登校』 and 学生の一日（月曜） 『帰宅』 PDFs covers "must do"
http://www.japanesepod101.com/store/pro ... ctid=18103
There are probably a lot of conversations that use it, but it might not have been pointed out as a grammar point - especially in the Lower Intermediate and Intermediate levels.
so maybe it's time that we cover it again. it's always good practice!
marky
