If your looking to use this information in practical speech, then yeah and ok coupled with genuine and positive (but not over the top) body language is your best bet. I think this although simple and obvious is certainly the most commonly used in informal conversation in Britain and equivalent to your talk example.

If you're looking to use this information in practical speech, then yeah and OK coupled with genuine and positive (but not over the top) body language is your best bet. 

I think this, although simple and obvious, is certainly the most commonly used in informal conversation in Britain and equivalent to your talk example.