I guess bad grammar / spelling could suggest
you might not know it so well...
because if they have to decipher a meaning out of it
you wont get full marks, cos its probably not 'logical or succinct'
so no band 6, if you stop making sense with your words
I dont know anything about double marking, sounds
pretty dodgy if they've found soo many mistakes
with each other's work that they need to double mark :S