"spelling":{"Spelling", "Capitalisation"},  
    "punctuation": {"Punctuation"},
    "articles": {"Articles"},  
    "vocabulary": {"lex_item_choice", "lex_part_choice",
                   'Category_confusion','Formational_affixes'},
    "grammar_major": {'Tense_choice','Prepositions','Agreement_errors', 'Redundant_comp'},
    "grammar_minor": {'Word_order','Noun_number', 'Numerals','Verb_pattern', 'Determiners'}