Latin Grammar

Latin grammar is morphologically rich — every noun, adjective, and pronoun marks case and number; every verb marks person, number, tense, mood, and voice. This explicit marking makes word order highly flexible (unlike English) and meaning precise even in complex sentences.

Grammar Sections

The Big Picture

Latin grammar can be organized around two systems:

Nominal System (nouns, adjectives, pronouns)

5 declensions, each identified by genitive singular ending (-ae, -ī, -is, -ūs, -ēī). 7 cases: nominative, genitive, dative, accusative, ablative, vocative, locative. 3 genders: masculine, feminine, neuter. Adjectives agree with the nouns they modify in gender, number, and case.

Verbal System (verbs)

4 conjugations, identified by present active infinitive ending (-āre, -ēre, -ere, -īre). 6 tenses in indicative (present, imperfect, future, perfect, pluperfect, future perfect). 3 moods: indicative, subjunctive, imperative. 2 voices: active, passive. 4 principal parts give all stems needed for conjugation: e.g., amō, amāre, amāvī, amātus.

Key Grammatical Principles

1. Word Order is Flexible — Case Endings Carry Meaning

In English, "The lion kills the man" ≠ "The man kills the lion." In Latin, leo virum necat = virum leo necat = necat leo virum — all mean "the lion kills the man," because leo (nominative = subject) and virum (accusative = object) signal grammatical role regardless of position. Typical Latin word order is Subject → Object → Verb (SOV), but this is a tendency, not a rule.

2. Every Noun Has Grammatical Gender

Gender is largely arbitrary (not natural) and must be memorized. The genitive singular ending of a noun tells you its declension; the dictionary entry tells you its gender. Example: puella, -ae, f. = girl, 1st declension, feminine.

3. The Perfect vs. Present System

All six tenses derive from either the present stem (present, imperfect, future) or the perfect stem (perfect, pluperfect, future perfect). Latin has no continuous/progressive distinction — amō can mean "I love," "I am loving," or "I do love."

4. Aspect Markers vs. Tenses

The perfect tense in Latin often expresses a completed action with present relevance ("I have loved" or "I loved"). Context determines which English tense best translates a given perfect.

5. The Subjunctive Is Not Optional

The subjunctive mood appears in many required constructions: purpose clauses, result clauses, fear clauses, indirect questions, cum clauses, conditional sentences. You cannot read classical Latin without mastering the subjunctive. See Syntax for all uses.

Quick Reference: Verb Forms Count

Plus 6 infinitive forms, 4 participles, gerund, gerundive, supine — over 130 distinct verb forms per verb.

Reference

The standard online reference grammar is Allen & Greenough's New Latin Grammar, available free at dcc.dickinson.edu/grammar/latin. All grammar topic pages in this section cite A&G by paragraph number where relevant.