Hi i like to know it's true that some people believe that boys growing taller until 20 thanks?

A few: Unless the family has a tendency toward late growth, most male growth is done by 17-18. Linear growth continues until the growth centers close, (17-18 in most) some will have slower closure of the centers and continue at a slow pace to 20.An x-ray of the wrist and hand can be assessed for growth centers and determine if growh is still possible.