Does your child have difficulties knowing how much to write?  For instance, when they are asked to write an answer to a question would they write a couple of lines rather than a full response? 

This is very typical!  If you don't tell a child what is expected of them then they won't know.  To overcome this difficulty, I use a traffic light system.  At the top of the page, I use a green circle to indicate where the child has to start writing.  Then a red circle is used to show when the child can stop writing.  This can be moved depending on the requirements of the task.