Awhile and a while are both correct and acceptable but not interchangeable. Awhile (one word) is an adverb that means “for a while” or “for a period of time”. A while (two words) is a phrase that means “a period of time.” In the phrase a while, “a” is an article, and “while” is a noun that means “period of time.”
Combining the two words becomes a noun phrase that means “a period of time.” (A noun phrase means a group of words that function as a subject, object, or prepositional object.) Thus, use awhile as an adverb and don’t use it after a preposition “for” or “in.” Meanwhile, use a while as a noun phrase to mean “a short time.”
When to Use Awhile
Awhile as an Adverb
We use awhile as an adverb that means “for a while” or “for a short time.” Remember, awhile cannot appear after prepositional phrases. (Prepositional phrases are a group of words consisting of a preposition and its object.)
For example, in the sentence, “I haven’t seen you for a while,” “for” is a preposition, and “a while” is the object. Thus. we cannot say, “I haven’t seen you for awhile.”
Can you stay awhile while I prepare for dinner?
I sat awhile at the beach and enjoyed the sunset.
Amir dropped by at the office and waited awhile to see his former colleagues.
I want to work awhile and rest immediately.
I stayed awhile, then left the house.
When to Use A While
We use a while (two words) as a noun phrase to mean a period of time, especially a short one. Typically, it’s used with the prepositions “in” and “for.” Some common phrases with a while include a little while, a short while, and quite a while. Also, it’s used with the words ago or back (“a while ago/back”).
There are many phrases we use for a while. We say it’s been awhile when something hasn’t happened for a long time. “Quite a while” means “a pretty long time.” We say it happened after a while if something happens after a period of time.
It’s been a while since I last visited our old house; I could see the mould on the walls.
The president will meet you in the hall in a while.
We’ve known each other for a while.
Sometimes they take quite a while to process your order.
I noticed that the store alters the display of their items often. A while ago, they changed it again.
Awhile vs. A While: Which One is Correct?
While awhile and a while are both correct and may sound the same, they are different from each other, and one can’t be used for the other. Awhile is used as an adverb, and it’s a single word. Meanwhile, a while is a noun phrase and used after prepositional phrases. To conclude, use awhile when modifying verbs and use a while with “in,” “for,” “ago,” and “back.”
Longman Dictionary of Contemporary English Online. (n.d.). A While. In https://www.ldoceonline.com/ dictionary. Retrieved from https://www.ldoceonline.com/dictionary/a-while
Longman Dictionary of Contemporary English Online. (n.d.). Awhile. In https://www.ldoceonline.com/ dictionary. Retrieved from https://www.ldoceonline.com/dictionary/awhile
Merriam-Webster. (n.d.). Awhile. In Merriam-Webster.com dictionary. Retrieved from https://www.merriam-webster.com/dictionary/awhile
Merriam-Webster. (n.d.). ‘Awhile’ vs. ‘A While’. In Merriam-Webster.com dictionary. Retrieved from https://www.merriam-webster.com/words-at-play/awhile-usage