<p>Small errors like the one you pointed out should not be a big deal at all. Being informal in your essays is actually often better to provide a conversation tone. I recommend that you disregard the comment by @bomerr </p>
<p>Almost all essays–in other words every single essay except for one–I have seen where people are using contractions and especially informal words come off sloppy and unprofessional. In other words as if the writer never had a good English teacher that taught them well. </p>
<p>@bomerr There is a huge difference between being conversational and being sloppy. Slang isn’t appropriate, but I see no reason why contractions should be a problem. It’s a personal essay about yourself, not an academic paper. </p>
<p>As I said. There was one essay that I remember where the person succeeded in coming off “conversational.” The most prominent feature of that essay was that it was about the student’s sport coach. It was not the typical essay where someone is talking about what they want to study, what they learned, where they come off, etc. </p>
<p>In the case of the OP specifically, the act of introducing themselves, such as in a standard cover letter, makes the essay formal. </p>
<p>You guys are missing the point. OP is referring to the space between the comma and the next word. The contraction is irrelevant, OP was simply providing an example of his mistake.</p>