我今天不开心 I am not happy ; I'm not happy today

你今天不开心 You are not happy today ; Today you are not happy

我今天很不开心 Today I am very unhappy ; I am very happy today ; I today very unhappy

我今天也很不开心 I was not happy today ; I am very happy today

为什么今天你不开心 Why are you unhappy today

你今天好像不开心 Today you seem unhappy

今天我很不开心 Today I was very upset ; Today I very unhappy ; Today, I am very unhappy

今天非常不开心 Today's very unhappy ; Very happy today

今天他似乎很不开心 today he seems rather unhappy