QM - whilst some of the members of this board are very up tight about grammar and the English language as a whole, there is reason behind their rantings.
Making yourself understood, in all mediums, is very important - even more so as an Officer. Remember that most of those who write here are or have been where you want to be in the RAF. That means they have passed the tests you are yet to face and that they have pride in the RAF and the standards held.