• I’m fine, thanks. And you?
• Good thanks / Very well thanks.
• Great!
• Pretty good
• Not bad.
• Couldn’t be better! (positive response)
• Could be worse (positive response)
• Can’t complain (positive response)
• I’ve been busy.
• Same same.
• Not so great.
• Could be better (negative response)
• I’ve been better (negative response)

Are there others expressions you have heard of before?