I've been searching about the ability to use "one" and "someone" interchangeably but found almost nothing. So what's the difference between them and can they be used interchangeably, for example, in these sentences:
- There are numerous things (one, someone) could notice
- There is a hidden place (one, someone) might find
- If (one, someone) comes up to you and asks….
Best Answer
They are not interchangeable in meaning, although either one forms a grammatically correct sentence in your examples.
This "One" is, a 'generic you'. It refers to a generic/unspecified person. 'One' referred to FF when he wrote that, and to me when I read it, and to you when you read it (seperately to each one of us, not to all of us a a class of 'ones who tink that ...').
This "someone" is a 'generic specific' individual. When 'the "one"' in this sentence anticipates a resolution, he thinks "Won't someone do something? A person could have posted a more complete answer by now". If this answer that I'm writing is "more complete" (or if we ignore "more complete", and just anticipate "an answer"), then I have chosen to be that someone.
For a more thorough, formal approach, see the links posted in the comments (by tchrist and FumbleFingers). Also from FF, you will likely be better served at ELL (this is ELU).