Prepositions and Their Complements

Latin prepositions ordinarily stand before the noun phrase they govern: in urbe “in the city,” ad portam “toward the gate,” cum amīcīs “with friends.” Their complements can contain modifiers, and a few conventional patterns place the preposition inside or after associated material. These limited alternatives are structured; Latin does not generally strand prepositions as English does in “the person I spoke with.”

The first task is government. A preposition selects an accusative or ablative complement, and some select either with a change in spatial perspective. The overview of prepositions and case supplies the broader inventory. Only after fixing that constituent should a reader ask why it stands early, late, or around another word.

The ordinary preposition-first phrase

A preposition and its complement form a constituent. The complement can be a bare noun, a pronoun, or a larger noun phrase.

Ad governs accusative novum portum. Adjective-first order occurs inside the complement; the whole phrase ad novum portum marks a goal. This is ordinary (unmarked prose).

Both in hortō and cum avō are complete prepositional phrases. Initial nominative līberī, not the first noun after a preposition, controls plural lūdunt.

The balanced source and goal phrases are placed together before the verb in (unmarked narrative). English uses the same ordering here, but the Latin cases independently confirm each boundary: ablative after ab, accusative after ad.

Case distinguishes perspective

With in and sub, accusative commonly profiles motion toward or extension into a domain, while ablative profiles location within it. Position does not create this contrast; the case does.

Accusative plural castra presents the camp as the goal. This is neutral (unmarked prose). The contrast receives fuller treatment under in with accusative or ablative.

Ablative plural castrīs presents location. The minimal contrast is morphological, not a difference in word order.

Accusative mēnsam accompanies directed motion into the under-table region; ablative mēnsā locates the dog there. Real usage can depend on how an event is conceptualized, so the labels “motion” and “rest” are useful starting points rather than substitutes for meaning.

A modifier can surround the preposition

Latin sometimes places an adjective or demonstrative before a preposition while the noun follows it. The entire sequence remains one noun phrase under prepositional government. Familiar examples include magnā cum cūrā, hanc ob causam, and quam ob rem. This enclosure is polished and frequent enough for prose; it is not unrestricted scrambling.

The ablative adjective magnā and noun cūrā enclose cum. The preposition still governs the ablative phrase. Ordinary cum magnā cūrā expresses the same relation with less framing.

Accusative hanc ... causam surrounds ob. Initial placement also links the reason back to the preceding discussion.

Here aliquot ... annōs surrounds post. This (literary or polished narrative) arrangement is recoverable because post regularly governs accusative annōs. For elementary composition, post aliquot annōs is safer and fully idiomatic.

Cum with personal pronouns

With personal and reflexive pronouns, cum conventionally follows and attaches to the ablative form: mēcum, tēcum, sēcum, nōbīscum, vōbīscum. These are ordinary (unmarked prose) forms, not poetic inversions. Other prepositions normally precede their pronouns: ad mē, dē tē, prō nōbīs.

Mēcum is the regular Classical expression. The English sequence “with me” must not be copied as cum mē.

Reflexive sēcum refers back to the clause's subject, Lūcia. Nonreflexive cum eā would point to some other woman supplied by context.

With relative and interrogative quī, Classical prose normally keeps cum before the form: cum quō? “with whom?” and vir cum quō vēnī “the man with whom I came.” The fused personal pattern should not be extended mechanically.

This is neutral (unmarked prose). Latin does not ordinarily produce an English-style stranded equivalent of “Who did you go to the theater with?”

Postpositions and apparent exceptions

A small set of words conventionally follows its complement. Causā and grātiā govern a preceding genitive and mean “for the sake of”; tenus “as far as, up to” follows an ablative singular or sometimes a genitive plural. These are restricted lexical patterns, often (formal) or (literary), not evidence that every preposition can follow its noun.

Genitive pācis precedes ablative causā in a conventional (formal prose) phrase. Personal reference uses meā causā, tuā causā, and similar possessive adjectives.

Postpositive tenus follows ablative pectore. This usage is relatively (literary or descriptive) and should be learned as its own construction.

Poetry permits rarer anastrophe, placing an otherwise prepositive word after its complement for meter or emphasis. Such (literary) licenses do not define neutral prose and should not be generalized in composition.

Phrase placement in the clause

A complete prepositional phrase often comes early to set time, place, cause, or topic; it can also stand near the word it modifies or late as new information.

Initial post cēnam frames the event temporally. It is not the subject.

Final placement and nōn ante make the time contrastive. The internal preposition–complement order remains unchanged.

Cicero, In Catilinam 1.10, gives an authentic formal connective, reproduced without added macrons:

Quam ... rem encloses ob and links the command to the preceding argument. The phrase as a whole occupies first position in (formal oratory); its internal order creates cohesion and rhetorical weight.

Common Mistakes

1. Stranding the preposition like English

2. Using cum mē

3. Ignoring government inside enclosure

4. Using the accusative for location with in

5. Generalizing postposition from causā

Key Takeaways

Bracket preposition and complement, verify the governed case, and only then interpret where the phrase sits in the clause. Ordinary Latin is preposition-first; conventional enclosure, cum attached to personal pronouns, and a few postpositions form limited, learnable systems. Marked literary reversal must not be confused with the productive prose norm.