Agree with him/her. Tell him/her that actually the fourth year is not doing any work at the moment.
Try to use 倒 and 什么...都。
是啊！可是四年级的学生倒什么功课都没有。
[Comments]
Click on the Chinese to hear the sentences spoken.
Alternatively one can say 是啊！但是四年级的学生连一点儿功课都没有。