首先,comment既是动词又是名词,commentary是名词
comment：评论
eg:Thisis the first draft of the book.Please feel perfectly free to *comment on* it.(comment可与on搭配）
commentary（对书籍等的）评语,评注,评论；实况报道
eg:Stop shouting!I can\'t hear the football *commentary*.
希望对你有用