Is your story any good?
Does it kick ass? Does it rock? Does it move even yourself to tears? Is it the absolute best you’ve ever written in your life? Can you not imagine any editor rejecting it without falling into uncontrollable shakings of utter regret? Should the world be no longer deprived of this work of literary genius?
Note: Answer this question both for the story’s intrinsic qualities and for the English. Both should be as great as you can humanly get them. And if you’re not a native speaker, please note that you’re competing with tens of thousands of writers who are. Your English should be publication-quality, not Balkenende-quality; good enough to blend into a slush pile, not clunky enough to stand out—in the bad sense.