Contrary to the above post, I wouldn't worry too much about your level of written English. I do not remember having to take a written exam during selection. I have certainly seen enough examples of piss-poor grammar and spelling from commissioned officers to be certain that it didn't play a major part in their selection.
Do your best and good luck with your efforts to join.
Buoy, I'm sure the above post was banter, and so you won't mind me pointing out that this is how you spell 'laziness'. Also, one of your sentences does not make sense, maybe the 'the' should have been something longer. Let he who is without sin......