If someone uses "your" instead of "you're", or "then" instead of "than", etc, do you consider that improper grammar or improper spelling. I think that's improper spelling. But some will argue that they're spelling those words properly. My argument is that they're not trying to spell those specific words. They're trying to spell another word and just so happen to spell it in a way that creates a properly spelled word.
I think that grammar police on a bbs website are sad individuals. I know a lot more about grammar than most people here, but most of my posts are littered with poor grammar. In college, my English department offered two grammar courses to undergraduates: practical grammar and introduction to linguistics. Most of the aspiring English teachers took practical grammar because the course taught the dos and don'ts of grammar. The linguistics course was a different animal; it was more concerned with theory from a historical perspective, sentence mapping, etc. For example, most people who took practical grammar wouldn't have a clue what a modal auxiliary is, nor would they care to know. The same goes for noun phrases, verb participle. But to answer your question, it's tricky to know for sure. Since "your" is the possessive form of the word, it isn't clear to me that the offender would know he or she were trying to form the contraction "you are." About as deep as they are thinking about the word is that is SOUNDS right, so it must me right. But it could just be a typo. You know this issue also touches on the idea of prescriptive vs descriptive grammar. If somebody writes your the reason god made Oklahoma. Semantically speaking, I doubt anybody gets tripped up with meaning, so WHY isn't your the acceptable way to right the sentence? Because prescriptivist tell us it's unacceptable. But consider this: tonight used to be written as to-night and there are many more examples of how our written stylistics have changed to meet the needs of the general public. If you dismiss my example because you think a contraction is different, consider the fact that: I ran for mayor, I ran from the police. In this instance the same form of the word is being used in two completely different ways.
I would go with improper spelling. The context of the sentence points to the word that was meant to be used.
Agreed. Its a spelling mistake, not a grammar mistake. More precisely, its a spelling mistake that resulted in a sentence that was not grammatically correct.
Grammar. There's a difference between knowing how to spell something and knowing when to use it properly, and it's not even close if you just don't know that difference. ^^^ these is a WEINER state meant. ^^^