• can’t complain  (= nothing is wrong / I’m OK)

Hey Dave, how’s it going?
Can’t complain. How about you?
I’m fine.

  • Yourself?  (= And you? / You? / How about you?)

Hey Dave, how’s it going?
Not bad. Yourself?
Can’t complain.

  • I don’t see why not  (= there is no reason not to / sure)

Hey Dave. Fancy a drink later?
I don’t see why not. What time?
About 8.