雞同鴨講gai1 tung4 aap3 gong2
meaning:two or more people talking about different subjects, whilst they believe they are talking about the same thing.
This Chinese idiom is like the English phrase "Talking past each other.
ngoh5 man6 kui5 seung2 m4 seung2 yam2 di1 cha4 ， kui5 wa2 kui5 m4 seung2 yam2 jui3 ， jan1 hai6 gai1 tung4 aap3 gong2 。
I asked her if she would like to have some tea, she said she didn't want to get drunk, we were just like “a chicken talking to a duck”.