I was told that another alternative for 'a few minutes ago' is 'a short while ago'. Let's say I am a student of a 20- minute English phone class and my teacher asks me questions which I answer during the first 10 minutes of our class. On the second 10 minutes she corrects my sentences. She says, "A while ago you answered, 'I go to work yesterday'. It should be 'went'. Past tense." Is it correct to use 'a while ago' and not 'a short while ago'? The situation is very clear. We never talked before the 20-minute class. It means that she refers to the period of time within the 20-minute class. Thank you.
A "while" is a length of time that is not defined. Used without a modifier, it implies one or more of the following:
- The exact amount of time is not important
- The speaker can assume that listener is familiar with the moment in time being referenced.
In your example, both of these probably apply. The teacher's point was made without specifying "10 minutes ago" because you knew of the conversation she was referencing.
The use of "short" or "long" becomes necessary if a more specific, but still vague, length of time is required for clear communication. Let's continue with your teacher example.
Imagine that the conversation she was referencing had occurred not ten minutes before, but a week. When she says that you said something "a while ago," you might reply "I don't remember saying that." Then she might clarify, "Well, it was a long while ago."
In this example number 1 in my list above still applies. The teacher can remain vague about the exact amount of time because the specifics are not important. However, because you could not recall the moment she was describing, more context was needed.
For a final example, suppose your friend came up to you and said "I saw Brad Pitt at the grocery store!"
You would love to see Brad Pitt for yourself, so you want to know if he is likely to still be at the store. You ask, "When?"
If your friend answers "A while ago," you don't have any new information to help you. You would have to press them for more information.
If they answer "A long while ago," you might as well stay home and watch World War Z again, because there is no way Brad Pitt is still at the grocery store.
If they answer "A short while ago," then you can run out to your moped and zip over to the store. He might still be there!
One final qualifier: "a short while" and "a long while" aren't very common in American colloquial English. You'd be more likely to hear "a little while" and "a long time," respectively.
"A while ago" is correct. I have almost always heard "a while ago," but I'm American, so "a short while ago" might be more common in other parts of the world. The phrase "a while ago" is older, as you can tell from this graph. "A short while ago" is more specific about the time, but both phrases would be understood.