Grammar and Sentence Structure
Grammar and Sentence Structure tests whether sentences are complete, correctly formed, and consistent in tense, number, and reference.
Agreement
A singular subject takes a singular verb. Find the true subject and ignore phrases between it and the verb: 'The box of books is heavy.' Two subjects joined by and take a plural verb; subjects joined by or or nor agree with the nearer one. Indefinite pronouns such as everyone, each, and nobody are singular.
Tense and form
Keep tenses consistent unless the meaning requires a shift. Learn irregular past forms: went, wrote, took, brought. After a modal (can, must, should) use the base form: 'She must go', not 'must goes'. Use the past participle with have: 'have eaten', not 'have ate'.
Completeness and joining
A fragment lacks a subject, a verb, or a complete thought. A run-on joins two complete sentences without correct punctuation or a conjunction. Fix run-ons with a full stop, a semicolon, or a comma plus and/but/so.
Pronouns and modifiers
A pronoun must refer clearly to one noun and agree in number: 'Each student brought his or her book.' A modifier should sit next to the word it describes: 'Walking home, I saw the rain' is correct because I was walking.
Worked example
'Either the teacher or the students ___ responsible for the display.' A. is B. are C. was D. be Reasoning: With either...or, the verb agrees with the nearer subject, students, which is plural. The statement is general, so present tense are fits better than was. Answer B.
Traps
Matching the verb to the nearest noun instead of the subject; mixing past and present without reason; using a comma alone between two sentences; and leaving a pronoun with two possible referents.