Grammar in Action – Awhile versus A While

A couple of weeks ago, I began to wonder what the actual rules were for using "awhile" versus "a while."

Here's what I found:

Grammatically, a while is a noun phrase in which "a" is an article and "while" functions as a noun meaning "a short period of time"; awhile is an adverb meaning "for a while." In other words, the meaning is the same, but the structure is different: the word awhile has "for" built into its meaning.

The test of which to use is to consider whether "for a while" may be used in the sentence where we intend to place (or have placed) the word awhile – without changing anything else.

Using the "for a while" test makes this decision easy, as we see in the sentence below:

The model is old and in the way, and I think you have to move on after a while.

I told him it was no big deal to continue waiting. After all, I'd already been there awhile.

In the first sentence, obviously we wouldn't say "move on after for a while," so we know that a while is the correct choice; however, we could add say "for a while" in the second sentence, making awhile the correct choice for that sentence.