第一句:
"are not allowed"是 被動式
"Many Hong Kong students are not allowed to ..." 意思是學生不被准許 ... (即學生不被學校准許...)
若採主動式,可以這樣說:Many schools do not allow their students to ...意思是學校不准許學生...
第二句:
"don't allow ..." / do not allow ...無疑是主動式。
但 "Many Hong Kong students don't allow to ..." 這句子並不合道理。是學校不准許學生...,而非學生不准許...