Campus Press
The strange grammar of 'need' as modal auxiliary

English Plain And Simple

(2114th of a series)

A HALLMARK for correctness in English grammar is subject-verb agreement, which demands that in a sentence, the subject and verb must always agree in number. If the subject is singular, its verb must take the singular form ('She dreams every night'); if the subject is plural, the verb must take its plural form as well ('They quarrel a lot.')