Look, it really depends - I've seen students when I've worked in schools who are really that bad at English (the fault of society and the school system in this country for not giving them the help they needed all the way through - one of my pet hates, but I'll try to resist that tangent) who would without a doubt fail Advanced. Unfortunately, they are not likely to do particularly well in Standard either. If you get the right help, you can probably do perfectly well in Advanced, but it's really difficult for people to give adequate advice without actually seeing the standard of your work. If you get really organised and hand in the work early to your teacher for feedback and help to improve it, then hand it in after applying that feedback (I'd correspond with your teacher several times with several drafts before handing it in, if at all possible) you should be fine. There are plenty of places you can get external help, as well. I edit and provide HSC assessment help, and I'm sure you'd find others who do the same - in fact, you may even have someone in your family who is willing to help you. Don't try to get through the HSC on your own strength - find the right help for you, and try to keep contact up with your teachers. They're in the best position to help you improve your marks, and most teachers love to have students show an interest and dedication.
