Often in IELTS speaking you are asked if you agree or disagree with something. Instead of just saying 'I agree' or 'I disagree', use these more complex phrases to say how much you agree or disagree with something.
I couldn't agree more with a total ban on smoking. It would be good for the health and well-being of the whole country.
I wholeheartedly agree that youngsters need to be encouraged to do more exercise than spending all their free time playing computer games.
I agree to a great extent that we need to do everything we can to protect the environment, but I would be unlikely to give up my car despite the damage it causes.
I agree to some extent with banning cars in city centres, but it would then possibly result in people not going into them and shops would suffer a downturn in trade as a result of this.
I partly agree that space travel is important, however, there are more important things to spend money on.
I totally disagree with the idea of banning children from fast food restaurants. If you ban something outright*, it makes it more attractive.
I couldn't disagree more with the death penalty. It is barbaric and has no place in modern society.
*to ban something outright = to ban something completely