to us, what we look for in prospective players (for our advanced RP) is primarily commitment and ability to plan. Sure, a certain level of grammar and lingual structure is nice, but its more important to consider what they achieve with their posts. Someone could (at least in theory) write a ten-page post with flawless grammar, yet achieve next to nothing for the story. Similarly, a lingually "weaker" player could achieve a lot with just a paragraph or three.