Aside from V-2 already commented on, I'd like to add that spelling mistakes such as > "it's" as a possessive are mostly native-speaker exclusive. Your/you're,

Aside from V-2 already commented on, I'd like to add that spelling mistakes such as > "it's" as a possessive are mostly native-speaker exclusive. Your/you're, there/their, etc. spelling mistakes you just don't see non native speakers make. This is because they're just that, spelling mistakes. So while native speakers know what they mean but it's just associated with a sound in their head, they just write out that sound. Non natives on the other hand usually think about the grammar, the right word, etc. I don't think I've ever met a non-native speaker that makes the there/their mistake e.g.