How do you tell someone that they are wrong without sounding rude or without offending them? Try to reduce the directness of the address. And how do you do that? By using expressions like ‘I’m sorry but…,’ ‘I’m afraid…,’ ‘I don’t think…’ ‘Don’t mind my saying so, but..’
I’m sorry, but that’ s not right.
I’m sorry, but you seem to have got it wrong.
I’m afraid that’ s not right.
I’m sorry, but you seem to have missed a point here.
Actually, things are quite contrary to what you’re saying.
I’m afraid you’re mistaken.
I don’t think you are right about that.
I don’t think what you are saying is right.
Don’t mind my saying so, but you’re mistaken/you’ve got it wrong.
You are wrong.
That’ s all wrong/rubbish.
That’ s nonsense.
You are not making any sense.
Where did you hear that? It’ s all rubbish!
What are you saying?