"I haven't met you before" =>I said to the man "I have never come here before" =>Minh said  "Your sister has eaten too much chocolate" =>Susan told Jack "I haven't met you since this morning" => Jane told Dat  "I haven't tried this restaurant yet" =>My dad said

I said to the man that I hadn't met him before.

Minh said that he had never come there before.

Susan told Jack that his sister had eaten too much chocolate.

Jane told Dat that she hadn't met him since that morning.

My dad said that he hadn't tried that restaurant yet.