Can I say "I haven't written to you for a long time" instead of "for a while"? And what exactly does "for a while" mean in that phrase?
"While" (noun) - means a period of time. Examples:
- "We chatted for a while."
- "They didn't see each other for a while."
Another good question to ask ourselves is: How long is "a while"?
- "You'll have to wait a while" usually means "You'll have to wait a long time." However the time value differs according to context; it can be "a minute", "an hour", "a day", "a week" and e.t.c.
"Quite" often modifies "while" and often means "for a long time":
- I haven't seen him for quite a while.
"Short" and "long" can also modify "while":
- It's been a short while since I've heard from him.
- He has been sitting here for a long while.
"Long time" - means a long period of time. Examples:
- "I haven't seen you for a long time."
- "It takes him a long time to come here."
Note: you can use "long" as a noun to imply the same meaning:
- I haven't seen you for long = I haven't seen you for a long time
Depending on what you wish you say you can use either!