When writing, one is always compelled by the nagging urge to expound their vocabulary exponentially instead of allow more natural language to suffice. By using words which resemble "academic" language in order to achieve an illusion of intellect, one sacrifices clarity for a flowery mess. Just because you use four syllable words doesn’t mean you will get that A. You merely need to display your ability to be concise and focused. By attempting to utilize words you are unfamiliar with, you are placing your work in the hands of the facade you endorse instead of your piece as a whole. Why sacrifice precision for quality? A teacher will more than likely commend you for a focused concrete essay than one which was fluttered with incomprehensible language. It's like sailing out to sea before you learned to swim. Yeah, it is brave, but also rather stupid. That is not to say you shouldn’t try to broaden your lexical belt, but do it with caution. If you’re comfortable with a word, go for it. Hold your chin high and proud as you exploit your linguistic excellence. Yet, if you are not that sure, stick to what you know. Clarity is all they really ask for. You can't argue against clarity. If you’re spouting words that make no sense while you are unaware they make no sense, then how could that help? Simple is sometimes best. Keep it simple and concise.