may

      （有可能但不肯定）也许，可能used to say that sth is possible

      （转折前所述情况属实）也许，可能used when admitting that sth is true before introducing another point, argument, etc.

      （征求同意或表示允许）可以used to ask for or give permission

      （礼貌地评价或提问等）可以used as a polite way of making a comment, asking a question, etc.

      （表示愿望）但愿used to express wishes and hopes

      （表明目的）可以，能够used to say what the purpose of sth is