Subject-Verb Agreement
Subject-Verb Agreement (SVA) is one of the most important principles of the way nouns and verbs interact. Every sentence and clause MUST satisfy SVA, or that sentence or clause is not a complete thought, hence it is not either a sentence or a clause.
For a sentence or clause to satisfy SVA, the subject and the verb of the sentence or clause MUST agree in number and person.
Note: Expressed subjects (nouns, pronouns, and adjectives in the nominative case) are, by definition, in the third person. (Expressed subjects are opposed to embedded subjects, i.e., the subject as indicated by the Latin verb's personal ending.)
SVA Satisfied
• Ego (first-person singular personal pronoun) sum (first-person singular present tense of the verb “be”).
SVA Not Satisfied
• Ego (first-person singular personal pronoun) est (third-person singular present tense of the verb “be”).
SVA Satisfied
• Poeta (third-person singular noun as expressed subject) scripserat (third-person singular past perfect tense of the verb scribo, scribere, scripsi, scriptum “write”).
SVA Not Satisfied
• Poeta (third-person singular noun as expressed subject) scripseratis (second-person plural past perfect tense of the verb scribo, scribere, scripsi, scriptum “write”).
For a sentence or clause to satisfy SVA, the subject and the verb of the sentence or clause MUST agree in number and person.
Note: Expressed subjects (nouns, pronouns, and adjectives in the nominative case) are, by definition, in the third person. (Expressed subjects are opposed to embedded subjects, i.e., the subject as indicated by the Latin verb's personal ending.)
SVA Satisfied
• Ego (first-person singular personal pronoun) sum (first-person singular present tense of the verb “be”).
SVA Not Satisfied
• Ego (first-person singular personal pronoun) est (third-person singular present tense of the verb “be”).
SVA Satisfied
• Poeta (third-person singular noun as expressed subject) scripserat (third-person singular past perfect tense of the verb scribo, scribere, scripsi, scriptum “write”).
SVA Not Satisfied
• Poeta (third-person singular noun as expressed subject) scripseratis (second-person plural past perfect tense of the verb scribo, scribere, scripsi, scriptum “write”).