Sometimes, sounds are lengthened for emphasis. For example, see "とっても versus とても". What are the rules governing this process? Are there restrictions on where lengthening can be inserted? とっても or ...
Why is は used at the end of こんにちは? Is the last letter the particle は, or is there a different explanation? I suppose you could equally ask "Why is こんにちは pronounced 'konnichiwa'?" - I guess gaikokujin ...
I've had a teacher flatly tell me that とっても is incorrect, but I do see it written here and there and I'm pretty sure I hear it as well. Is it just so informal relative to とても that I should never use ...