Ablative of Comparison
After a comparative adjective or adverb, Latin offers two ways to say "than": quam + a matching case (altior quam arborēs, "taller than the trees"), or — more compactly — a bare ablative on the second term (altior arboribus, same meaning).
Think of the bare ablative as a leftover from separation: starting from the trees, you climb to the taller thing.
Catullus does this constantly — plus oculis meis amārem, "I would love (you) more than my own eyes." The trap is knowing when each option is allowed: the bare ablative needs the first thing compared to be in the nominative or accusative, and falls apart when the second term is anything but a single noun.
Anything more complicated, and quam takes over.
Learnings0 core · 1 AP claim
AP framework claims (1)— verbatim from AP CED
Both render English "than" — bare ablative is compact, quam is the safe default.
Bare ablative requires the first term in nom. or acc. AND the second term a single noun. Anything else: use quam.
See It In Action
— Cat. xiv. 1
Catullus uses the bare ablative because the first term (te) is accusative and the second (oculis meis) is a clean noun phrase — exactly the conditions A&G 406 names. Quam meōs oculōs would mean the same thing in plodding prose.
— Aen. x. 129
Two bare ablatives chained off one comparative — Vergil tightens the line by skipping quam twice. The implied subject is nominative, so the construction is fully licensed.
— Cat. lxxxii. 2
Negative-leaning context (si quid, "if anything") + nominative first term = textbook bare ablative. Notice how oculīs sits right beside cārius — proximity is part of why the reader hears the comparison.
— Sall. Cat. li. 42
Sallust uses quam (not the bare ablative) because the second term is a whole clause (in nobis, qui ...) — A&G 407.a.n1 requires quam the moment the second member carries its own subordinate structure.
Both translate as English "than." Latin chooses based on the case of the first term and the shape of the second term.
compact "than X" — single noun, first term nom./acc.
altior arboribus
taller than the trees
second term echoes the case of the first; needed when first term isn't nom./acc. or second term is complex
altior quam arborēs
taller than the trees
Tip: Ask two questions: (1) Is the first term nominative or accusative? (2) Is the second term a single noun? Two yeses → bare ablative is allowed. Any no → use quam.
In Vergil's nec Clytiō genitōre minor nec frātre Menestheō (Aen. x. 129), what work are Clytiō genitōre and frātre Menestheō doing?
Study Tips
- •When you spot a comparative (-ior, -ius, plūs, minus, magis), look immediately right for either quam or a bare ablative — those are your two "than" signals.
- •Drill the test: is the first term in the nominative or accusative AND the second term a single noun? If yes, the bare ablative is fair game. If no, write quam.
- •Watch for the negative-sentence pull: after nihil, nēmō, nōn, prose almost always uses the bare ablative — nihil dētestābilius dēdecore ("nothing more loathsome than disgrace").