知识探究1
What's the matter with you,Tony?
What's the matter with you?意为“你怎么了?/你有什么麻烦/烦恼事了?”，常用来询问某人患了何种疾病或遇到了何种麻烦。英语中表达此意思有以下几种常见的表达:What's the matter with
you?=What's the trouble with you?-What happened toyou?

知识探究2
Well, I'm not sure about that.
be sure about = be sure of意为“对.…….有把握;确信.....”，后面接名词、代词或v.-ing形式。
Never mind.
本句是日常用语，常用于原谅别人。