Quote Moonshine="Moonshine"Just spotted the spelling gaff 
 must TRY harder ( I blame Highfields school)'"
 must TRY harder ( I blame Highfields school)'" 
What spelling gaffe?
Tries is correct.
The only possible alternative is trys.
Try's is not a plural ... it means belonging to try.
Or there are letter/s missing.
As in an abbreviation of something.