Place, means, and prepositions
Use accusative and ablative constructions for motion, location, means, and accompaniment.
Build the idea, then use it.
Latin distinguishes being in a place from movement toward it and can express an instrument without an English-style preposition.
Place, means, and prepositions
ad urbem and in urbem express motion toward; in urbe expresses location. An ablative can also express means without a preposition, while cum with the ablative commonly marks accompaniment.
A preposition and case form one construction
Learn a Latin preposition with the case it governs. ad plus accusative expresses movement toward or location near; ex or dē plus ablative expresses movement from or down from; cum plus ablative commonly expresses accompaniment. in changes with case: in urbem, accusative, is motion into the city; in urbe, ablative, is location in the city.
The contrast is semantic, not a rule that the accusative always moves. Many accusatives are direct objects, and many ablatives express relationships other than place. First identify whether a preposition governs the noun, then interpret that whole phrase. urbs, urbis is a third-declension noun, so urbem and urbe look different from the first two declensions but fill familiar case roles.
Means is not the same as company
The ablative of means normally has no cum: gladiō pugnat, ‘he fights with a sword.’ The sword is the instrument. Accompaniment normally uses cum: cum amīcō pugnat, ‘he fights with a friend.’ The friend accompanies the subject as a person rather than serving as a tool. English uses ‘with’ for both, so the Latin construction preserves a distinction English wording can hide.
Read puer ex urbe cum amīcō ambulat. ex urbe gives the source ‘out of the city’; cum amīcō gives accompaniment ‘with a friend’; ambulat supplies the motion. Now compare ad urbem ambulat, ‘he walks toward the city,’ and in urbe ambulat, ‘he walks in the city.’ Each case answers a different spatial question.
Map the relationship before the noun
ad plus the accusative means toward or near; in plus the accusative expresses motion into, while in plus the ablative expresses location. cum plus the ablative marks accompaniment. A bare ablative can express means: gladiō pugnat, ‘he fights with a sword.’
Learn these five words in context.
Read them once now; the check will ask you to retrieve them.
- urbs
- city
- ad
- to, toward, or nearTakes the accusative.
- cum
- withOften accompaniment with the ablative.
- ex
- out of or fromTakes the ablative.
- gladiō
- with a swordAblative of means here.
Puer in urbem ambulat; puella in urbe est.
Puer in urbem ambulat; puella in urbe est.
The boy walks into the city; the girl is in the city.
- 01
in urbem uses the accusative for motion into.
- 02
in urbe uses the ablative for location.
- 03
The preposition stays the same, so the noun ending carries the contrast.
Source focusAllen and Greenough §§398–429+
Keep this citation attached to the lesson’s claims. Source, genre, date, and purpose determine what the evidence can responsibly support.