....prosze sprawdźcie list....

Dear Sir or Madam!
I am writing to you regarding your article about contemporary youth. I do not agree with your opinion. Firstly, you should not generalize. It is not true that every teenager is interested only in libations, riots or conversations about clothes and cosmetics. Many young people like poetry, literature or art. Besides not all young people are bad to bone and selfish. For example, there are many young people who adhere to charities or work as volunteers. They do it to help necessitous people and, in my opinion, it is especially important virtue of them.
Youth is receptive to foreign culture and people and therefore contemporary teenagers can strive to eliminate intolerance in the world.
The fact is that conflict of generations is huge problem. Parents and teenagers should be realized about mutual problems and needs on special meetings at school.
Yours faithfully,
XYZ

Dear Sir or Madam(!) (tutaj powinien byc przecinek)
Besides not all young people are bad to THE bone and selfish. For example, there are many young people who 'adhere' (to slowo nie za bardzo) to charities or work as volunteers. They do it to help necessitous
people and, in my opinion, 'it is especially important virtue of them.' (cos tu nie tak...to nie jest gram.)
The fact is that conflict of generations is 'A' huge problem. Parents and
teenagers 'should be realized' (nie, nie tak...should discuss?) 'about' THEIR mutual problems and needs 'on' AT special meetings at THE school.