What's the matter?
你怎么了?
Are you okay?
你没事吧?
What happened?
到底怎么回事?
What are you worried about?
你担心什么?
Is something bothering you?
你有什么烦心的事吗?
What's on your mind?
你担心什么呢?
You look sad today.
你今天怎么满脸的不高兴。
Why are you so glum?
你怎么闷闷不乐的呀?
Something is wrong with you today.
你今天有点儿不大对劲。
Who are you irritated with?
谁让你烦躁了?