Grammatical Category & Usage	Description of Errors or Misusage
Word Derivations	Noun, verb, adjective, and adverb form confusion/misuse
Articles	Incorrect choice; unnecessarily used; omitted when needed
Nouns	Singular/plural or count/non-count confusion; failure to use proper unit expression with non-count noun
Pronouns	Lack of agreement with antecedent, ambiguous antecedent, no antecedent; unnecessarily used, not used when called for, incorrect form
Auxiliaries and Modals (Aux-words)	Incorrect choice; omitted when needed; unnecessarily used
Verb Forms	Incorrect form (based, d-t-n, -ing, +s, past) incorrect verb choice; unnecessarily used; omitted when needed; incorrect use of two word verbs
Verb/Auxiliary Agreement with Subject	+s/no –s confusion; ignorance of true nucleus of noun phrase
Verb/Auxiliary Agreement with Time	Lack of agreement with general context, with time signal, with other verbs, in complex sentences, and/or with compound noun clauses
Modifiers	Incorrect form (ing/d-t-n, adjective/adverb, etc.); incorrect order; incorrect position in sentence
Comparatives & Superlatives	Inappropriate comparison; incorrect comparative formation; incorrect superlative formation
Basic Sentence Structure	Incorrect syntax (word order); incorrect shifter; omitted object with transitive verb
Expletives there or it (Dummy Subjects)	Unnecessarily used; omitted when needed; followed incorrect form of verb-aux-word
Sentence Complexity	Simple; compound; complex; conditionality; use of subordinate clauses
Incomplete Sentences (Fragments)	Omission of subject; omission of verb; prepositional phrase used alone; subordinate clause used alone; noun phrase used alone; half sentence used alone
Coordination (Compounding)	Run-on sentences; comma splice; faulty parallelism; incorrect conjunction choice; incorrect compounding method; unnecessary repetition
Subordinate Clauses	Incorrect clause formation; poor relationship to main sentence; incorrect subordinator
Relative Clauses	Incorrect clause formation; poor relation to modified noun; incorrect relative pronoun
Half-Sentences (Participial Phrases, Absolute Phrases)	Incorrect formation; poor relationship to main sentence; different subjects
Nominal Clauses or Phrases	Incorrect clause formation; incorrect introducer of substitution; poor relationship; -ing/to + base form misuse/confusion
Passive Transformation	Used inappropriately; incorrect formation
Indirect Object Transformation	Used inappropriately; incorrect formation
Transition Words	Not used when called for; used inappropriately; poor or incorrect choice
Variety in Writing	Insufficient variety of basic sentence patterns; insufficient variety of combining methods
Commas	Incorrect use with shifters; comma splice; incorrect use with relative clauses; incorrect use with half-sentences; incorrect use with (non-restrictive) added information
Vocabulary	Too limited; incorrect word choice
Prepositions	Incorrect choice; omitted when needed; unnecessarily used
Other Problems