Verb errors

All errors in verb tense or form, including relevant subject-verb agreement errors.

Noun ending errors

Plural or possessive ending incorrect, omitted, or unnecessary; includes relevant subject-verb agreement errors.

Article errors

Article or other determiner incorrect, omitted, or unnecessary.

Wrong word

All specific lexical errors in word choice or word form, including preposition and pronoun errors. Spelling errors only included if the (apparent) misspelling resulted in an actual English word.

Sentence structure

Errors in sentence/clause boundaries (run-ons, fragments, comma splices), word order, omitted words or phrases, unnecessary words or phrases, other unidiomatic sentence construction.