The object of this code is to let you
look at your mistakes on your own and
learn from them.
sp Spelling e.g. Friends not frinds
gr Grammar e.g. Lots of money not many money
pr Preposition eg. I live in London not I live at London
pu Punctuation e.g. I like milk not i like milk
vt Verb tense e.g. I went to Spain in 1995 not I have gone to Spain in 1995
wo Word order e.g. I like dancing very much not I like very much dancing
ww Wrong word e.g. I missed the bus not I lost the bus
mw Missing word e.g. I saw a bird not I saw bird
r Repetition i.e. saying the same again and again and again etc.