Your = possessive. i.e. Your car, your boat, your rotten grammar.
You’re = a contraction for “you are”. i.e. Your rotten grammar makes you look like you’re an idiot.
This is not aimed at the casual blogger. This is for people in professional fucking journals who, at least in theory, have fucking editors to catch shit like that.
You writers out there really oughta1 figure this stuff out, too, ya know. In theory, your tools are your words and you’re making yourself look like an idiot if you cannot employ your tools to your advantage to show you’re a professional.
1Yes, yes, yes, I’m aware when I write, I use colloquial terms. You’ll also note that I’m specifically doing so as a technique to mimic folksy speech on purpose. I am perfectly capable of writing formally when necessary. It is more often necessary in the course of my own work to create a rapport with my audience. This generally requires a certain rhythm to my “voice” best expressed by my native accent and speech patterns. If you think it is not a specifically-chosen technique, you’re sadly fooling yourself about the thought a writer puts into her craft!