be likely to do和be likely doing的用法·辨析

be likely to 固定搭配表示可能.=eg:It is likely to rain.好像快要下雨了
be likely doing 很少见,但口语中有 sb be most likely doing sth（某人很可能正在做某事）.这种用法中的likely实际是起到句首状语的作用,与前面的be和后面的doing 并不构成固定搭配,原型是 most likely,sb be doing sth