How can you grow a full beard?

This depends. If you have reached puberty then you will start to grow hair where you haven't been able to before. This mainly on the legs, arms, in the armpits, around the genitals and on the face. Not every teen-boy will be able to grow a full beard though. Asian and Middle-Eastern males are more likely to be able to grow full beards quicker than European, American males. But generally once an adult you can grow a beard. You just don't shave until you have reached the desired effect. You can trim your beard at any length then.

Dude. The answer is in the question. how to grow a full beard? You GROW A FULL BEARD. Just grow it. wait for the beard to grow on your face and WHAA LA! Suddenly you have a full beard. Pretty simple.