1、You won't able to stuff him.應該是You won't be able to stuff him.
be able to do sth.有能力做某事.
won't = will not 將不會的意思.
所以你說的打敗應該是指stuff了.但是stuff 原意沒有打敗別人的意思,可能是美國俚語里面的用法吧,俚語里stuff有：誆騙,作弄,欺負,丟掉,處理掉的意思.
2、In ability she towers over all the others in her class.
主句是：She towers over.她超過.
主語是：she 謂語是：tower.
all the others in her class 是賓語,就是她超過的對象.
in ability 是定語,就是她在哪個方面上超過.