What do you think we should do to improve our English?这样说可以吗？

do you think在这里是作插入语.What (do you think) we should do to improve our English?

Do you think what we should do to improve our English?肯定不对！
前面的也不正规，地道！
应当是：
How shall we do to improve our English in your opinion?
What's your suggestions to improve our English?

前面的正确，后面的可以说成Do you think we should improve our English？意思是：你是不是觉得我们应该提高我们的英语？

前面那个, 后面那个语法不对

第一个语法正确，但是表达不地道；第二个就不用说了，肯定错。