One thing that annoys me...
If someone says "One things that annoys me about you is you always contradict me" - does it imply that there may be more things that annoy them?
Is it correct to say "The one thing that annoys me..." if I want to say it's the only annoying thing?
Is it correct to say "One thing that annoys me about you is THAT you always contradict me"?

Thanks:-)

Question

One thing that annoys me...
If someone says "One things that annoys me about you is you always contradict me" - does it imply that there may be more things that annoy them? 
 Is it correct to say "The one thing that annoys me..." if I want to say it's the only annoying thing?
Is it correct to say "One thing that annoys me about you is THAT you always contradict me"?

Thanks:-)

Answer

"One thing that...." It's really a figure of speech. It can mean there is only one thing, or it can mean there are more. Technically, it's an easier way of actually pointing out things that annoy you. It's a way of communicating a sensitive issue to another person.

"The one thing....." This is rather direct, and is an intended criticism. So careful!

Answer

the one thing sounds odd. Should be OK though. Actually you should always add the "that" in that case.