Familiae emptor patrimonium mancipatione accipit.

Here familiae is genitive singular, not nominative.

It depends on emptor and means of the family / of the estate. So familiae emptor means buyer of the estate or purchaser of the household property.

It is not the subject because the subject is emptor, which is nominative singular. The ending -ae can be either genitive singular or dative singular in the first declension, so you have to decide from context. Here the genitive makes sense; the dative does not.

It is more than just a random combination of words: familiae emptor is a technical legal expression in Roman law.

Literally, it looks like buyer of the family, but that can be misleading in English. In this kind of legal Latin, familia can refer not just to family members, but to the household estate/property. So the phrase is better understood as something like purchaser of the estate.

That is why a translation may sound less literal than the Latin words suggest at first glance.

Patrimonium is accusative singular, the direct object of accipit.

So the structure is:

• emptor = the subject
• accipit = the verb
• patrimonium = what he receives

A beginner may wonder whether patrimonium could be nominative, since neuter second-declension nouns have the same form for nominative and accusative singular. That is true in form, but here syntax makes its function clear: accipit needs an object, and emptor is already the subject.

Mancipatione is ablative singular of mancipatio.

Here it is an ablative of means/instrument, meaning by means of mancipation or through mancipation.

Latin often uses the ablative without a preposition to express the means by which something is done. So:

• mancipatione = by mancipation

Because Latin does not always need a preposition where English does.

In English, we usually say by mancipation or through mancipation. In Latin, the ablative case by itself can express that idea. So mancipatione already contains the sense of by/through.

This is very common in Latin:

• gladio pugnat = he fights with a sword
• consilio vincit = he wins by strategy
• mancipatione accipit = he receives by mancipation

Because the subject is third person singular: emptor = the buyer / purchaser.

So the verb must also be third person singular present active indicative:

• accipio = I receive
• accipit = he/she/it receives

The ending -t is the normal third-person singular ending in Latin.

Latin word order is much more flexible than English word order because Latin uses case endings to show grammatical relationships.

English depends heavily on position:

• The buyer receives the estate
  not
• The estate receives the buyer

Latin can move words around more freely because the endings tell you what each word is doing.

In this sentence:

• Familiae emptor comes first as the subject phrase
• patrimonium comes next as the object
• accipit comes last, which is very common in Latin

So even though the order feels unusual to an English speaker, it is perfectly normal Latin style.

Latin has no articles like English the or a/an.

So a noun like emptor can mean:

• a buyer
• the buyer

and patrimonium can mean:

• an inheritance / estate
• the inheritance / estate

Context tells you which English article is best. That is why translations may differ slightly even when the Latin is the same.

They are related, but not exactly identical.

• familia in this legal phrase belongs to the fixed expression familiae emptor
• patrimonium refers to the estate/inheritance/property being received

So one word is part of the title or role, and the other names the thing involved in the action.

To an English learner, this can feel repetitive because both may be translated with words like estate or property, but in Latin they are doing different jobs in the sentence.

They are:

• familia, -ae = family, household, estate
• emptor, emptoris = buyer, purchaser
• patrimonium, -ii = patrimony, inheritance, estate
• mancipatio, mancipationis = mancipation
• accipio, accipere, accepi, acceptum = receive, accept

Knowing the dictionary form helps you recognize the case or verb form you are seeing in the sentence. For example:

• emptor comes from a third-declension noun
• mancipatione comes from mancipatio
• accipit comes from accipio