debugging makes a person a better programmer

[broebel]

I'm just wondering,

people tell me that helping to debug someone elses program is a really good
way to learn to understand the language it's programmed in.

My question is: from wich point of can someone start to try to help a
programmer by debugging or testing a program.

If indeed you already need a profound knowledge of the language than how can
you learn something about it? except for the fact that you see other
possibilities of way to programm.

Are there pages that can be found with programs to help understand the
language or the way to use the language.

thanks in advance
 ik