First of all, please make a note that most of the child is having this kind of negligence because of lesser concentration on their day to day activities. So you need not worry on this because the improvement of your child will definitely be happen with their age.
Also, for the better improvement in concentration of your child, you may try to convince him with love to practice more and more in written to improve their vocabulary.
Apart from the above, if you realize that your child is much more different with the other child, please consult to a doctor.