Can anyone explain when to use ´bak´ or ´bakın´, and likewise

izle / izleyin

dinle / dinleyin

etc,

What is the difference, it´s both ´emir kipi´ değil mi?

I´ve seen this lesson: http://www.turkishclass.com/turkish_lesson_72 but this doesn´t explain when to use either. 

Here´s a good link:

http://www.turkishlanguage.co.uk/imperative.htm

Haha, I should have know that

Thanks D.

Thanks M. I guess the difficulty is when I´m among friends/family: do I still use bakin? The most polite -iniz form I understand, but the less-polite forms are more difficult for me to distinguish. Turkishlanguage says the -in is the polite form already. So -iniz is even more polite? There are 3 degrees of politeness? I can image I would say ´bak´ to a child for warning for example. But to my friends? 

u can use BAK with friends also or BAKSANA

Yes, when to adress to A friend.