YOU SAID:

i have nothing to do at school even though i could be doing school

INTO JAPANESE

学校はできても学校では何もしません

BACK INTO ENGLISH

I can do school but I don't do anything at school

INTO JAPANESE

学校はできますが、学校では何もしません

BACK INTO ENGLISH

You can go to school, but you don't do anything at school

INTO JAPANESE

学校に行くことはできますが、学校では何もしません

BACK INTO ENGLISH

You can go to school, but you don't do anything at school