Screw you的意思是：去你的!
例如：
Screw you,Jack!
杰克,你这个混蛋!
Screw you!I don't need you to tell me what to do.
去你的!我不需要你告诉我怎么做.
Screw you.Dad said we would stay home this summer.
去你的吧.爸爸说过我们今年夏天要呆在家里.
screw you up的意思是：害惨、搞死、弄得一团糟等.
例如：
On one hand,if dying was all you thought about,it could kind of screw you up.
从某方面来说,如果你总是想着自己是怎么死的,这也许会害惨自己.
The faculty members know that too.One told me:"You try to help them,then they screw you up!“
很多教职员工也知道这点,有人曾跟我说：“您尽力帮助他们,可他们却把您弄得一团糟.”
祝你学习愉快!