出典:Wiktionary
awhile (not comparable)
Awhile as means “for a while” is often considered incorrect to use with a preceding preposition, since one is already supposed: instead of “for awhile”, one should prefer either “for a while” or simply “awhile”. However, “awhile” as object for a preposition is used by renowned writers, is allowed by Merriam-Webster, and is consistent with how other adverbs of time and place are employed.
In Pennsylvania Dutch English, awhile is typically always used to convey such sense; the word is separated as “a while” for the first sense, whether preceded by a preposition or not. Compare “You may sit awhile” (inviting a person to sit while they are waiting) and “You may sit a while” (inviting them to sit for a length of time).
a while
少し前に.
a while ago
すぐに.
久々に
その時まで
until that time
あるときに
あの時
時としては
2時に