Grammar topic is a broad term that encompasses the rules and conventions of language. TENSE (5 letters) is a form of a verb that indicates when an action takes place, such as past, present, or future. Tenses (6 letters) is the plural form of TENSE, referring to the various forms of a verb. Nouns (5 letters) are words that refer to people, places, things, or ideas. USAGE (5 letters) is the way in which words are used in a sentence, including grammar, spelling, and punctuation.