Quite often, word differences are not recognized when they are spoken, but the differences are clear when they are written.
The word “awhile” and the phrase “a while” are quite different, although they may sound alike.
According to dictionary. com:
“These two terms represent different parts of speech. The two-word expression, a while, is a noun phrase, consisting of the article a and the noun while, defined as ‘a period or interval of time.’ The one-word, awhile, is an adverb that means ‘for a short time or period.’ Although these definitions are similar, and although the terms can sometimes be used interchangeably, there are a few simple rules that prove helpful in keeping them straight.
The noun phrase a while can and often does follow a preposition, such as for or in: ‘He said he would be home in a while.’ The adverb awhile cannot follow a preposition, a rule that makes sense if you revisit the definition of the term and drop it into a sentence such as the one above: ‘He said he would be home in for a short time or period.’ However, if we omit the preposition and rewrite it as ‘He said he would be home awhile,’ the sentence works with a slightly altered meaning.”
On the other hand, the word “another” is one word that is often pronounced as if it were two (a nother). In fact, some people use part of it (nother) as if it were a real word. The most common use is “a whole nother thing.”
It has worked its way into everyday vocabulary like “un-f_____g-believable.”