To be honest, the biggest problem for most undergraduate students, in terms of academic writing, is not only adapting to a far more structured and formal style, but also learning how to ascertain the difference between important, valid information and unnecessary, or even irrelevant material. In my experience, I would say it takes students their first year, if not longer. To appreciate what is required and to start to implement those requirements in their writing. What they really should be doing, if they are struggling with written assignments, is to seek help from the excellent support services which are available at the University.