Joyce, I have to say I would love to have had someone make me repeat my French sayings over and over again when at school, as then I wouldn't have sounded so English the first time I visited my penfriend.
Oh yes, I agree it's the best way to correct someone's accent and pronunciation if you catch their error straight away and help them out. I just wondered how long it can drag out a lesson.
I'm back in Chinese classes now, and the hardest thing with pronunciation is managing the tones, but getting the words out with a reasonable speed and decent phrasing.
Good luck! I always feel sorry for people learning Chinese because of the need to learn the tones. Cantonese is my mother tongue so thankfully moving to Hong Kong after living in Australia was not as bad as it could have been as I could follow conversations.
I did correct my friends sometimes but only if they had asked for help or if the tone was completely wrong thus changing their sentence to something totally different.
But occasionally I would get upset at the other people who would 'pretend' not to understand when it was pretty obvious what the person wanted and the tone was just slightly off. I don't think there's a need to embarrass someone who is at least making the effort to speak the local language.