A WHILE or AWHILE?

source: JamesESL English Lessons (engVid) 2013年3月7日
http://www.engvid.com/ "A while" or "awhile"? These words sound almost exactly the same, but one is a noun, and one is an adverb. In this lesson for advanced students, I'll teach you when to use each. Even native speakers get this wrong, so it might take a while, but if you watch the lesson and do the quiz, you will get it. http://www.engvid.com/a-while-or-awhile/