sir thisregarding my son who is very lazy i writing he knows all but does not write what should i do

All I can do is give you some links to some excellent study skills websites. The rest is up to him.

http://www.studygs.net/

http://www.how-to-study.com/

http://www.adprima.com/studyout.htm

(Broken Link Removed)

http://www.d.umn.edu/kmc/student/loon/acad/strat/

Good luck. =)