Avia dicit se, cum iuvenis esset, ad forum saepe fabas et hordeum emptum ivisse.

Because dicit introduces an indirect statement.

After verbs of saying, thinking, knowing, perceiving, etc., Latin very often uses:

• an accusative subject
• plus an infinitive

So in Avia dicit se ... ivisse, se is the subject of ivisse.

Literally, the structure is:

• Avia dicit = grandmother says
• se ivisse = that she went / herself to have gone

So se is accusative because it belongs to the indirect statement, not because it is the object of dicit in the English sense.

Also, se is reflexive: it refers back to the subject of the main verb, avia.

Ivisse is the perfect active infinitive of eo, ire (to go).

In indirect statement, Latin uses an infinitive instead of a finite verb. Since the action happened before the time of dicit, Latin uses the perfect infinitive:

• se ivisse = that she went / that she had gone

So even though English might say she says that she used to go or she says that she went, Latin expresses the earlier action with the perfect infinitive.

Because emptum is a supine in -um, used with a verb of motion to express purpose.

This is a standard Latin construction:

• venit rogatum = he came to ask
• misit petitum auxilium = he sent to seek help
• iit emptum = she went to buy

So:

• emptum ivisse = to have gone to buy

This is more idiomatic Latin than using an infinitive of purpose here.

A very literal breakdown would be:

• ad forum ... emptum ivisse = to have gone to the forum for buying ...

But in natural English: to have gone to the forum to buy ...

No. Emptum here is not an adjective agreeing with fabas et hordeum. It is the supine of emo.

So:

• fabas et hordeum = the things being bought
• emptum = to buy

It is best understood as a fixed verbal form used after a verb of motion.

That is why it stays emptum, even though:

• fabas is feminine plural
• hordeum is neuter singular

If emptum were an adjective, agreement would be different. But here it is not adjectival.

Because this is a cum-clause giving background time/circumstance, and such cum clauses commonly take the subjunctive.

So:

• cum iuvenis esset = when she was young

Latin often uses:

• cum
  • imperfect subjunctive for background in past time

The idea is not just a simple calendar-time when, but rather the circumstance in which the main action took place.

There are two main reasons.

1. It is a cum-clause of circumstance, which normally takes the subjunctive. So esset is expected after cum in this kind of sentence.

2. It is inside indirect statement, and Latin often uses the subjunctive in subordinate clauses that are part of reported speech or thought.

So cum iuvenis esset means something like:

• when she was young
• more literally, when she was in her youth

If the sentence were phrased differently and not in this construction, you might see cum iuvenis erat, but here esset is the normal choice.

Because it is a predicate nominative with esset.

The understood subject of esset is the same person referred to by se, namely the grandmother. In Latin, after forms of esse, the predicate noun/adjective is normally nominative:

• ea iuvenis erat = she was young
• therefore in the subordinate clause: cum iuvenis esset

So iuvenis is not an object. It describes the subject.

Yes. Iuvenis can refer to either a young man or a young woman, depending on context.

It is a third-declension word whose form does not change between masculine and feminine in the nominative singular. Here the context makes it clear that it refers to avia, so it means young or a young woman.

In this sentence, the natural translation is simply when she was young.

Because ad takes the accusative and expresses motion toward a place.

So:

• ad forum = to the forum

This fits with ivisse (to have gone), since the sentence is describing movement.

Compare:

• in foro = in the forum
• ad forum = to the forum

Because they are simply two things being bought:

• fabas = beans
• hordeum = barley

Latin can coordinate nouns of different number and gender just as English can:

• beans and barley

There is no grammatical problem in having:

• one plural noun
• one singular noun

Both are accusative because both are objects of the idea to buy contained in emptum.

Saepe means often, and it modifies the action of going to the forum to buy things.

So the sense is:

• she often went to the forum to buy beans and barley

Its position is flexible. Latin word order is much freer than English word order, so saepe can stand where the author wants it for rhythm or emphasis.

Yes. Dicit is present:

• Avia dicit = Grandmother says

But what she says is about an earlier time, so the indirect statement uses the perfect infinitive:

• se ... ivisse = that she went / had gone

So the sentence combines:

• present reporting: she says
• past action within the report: that she used to go / went

Yes, depending on context.

Strictly speaking, ivisse is perfect infinitive: to have gone. But because the sentence also contains saepe (often) and the background clause cum iuvenis esset (when she was young), English often expresses the idea more naturally as habitual past:

• Grandmother says that, when she was young, she often went to the forum to buy beans and barley.
• or ... she would often go ...
• or ... she used to go ...

So a smoother English translation may use habitual wording even though the Latin form itself is perfect infinitive.

A useful way to divide it is:

• Avia dicit — main clause
• se ... ivisse — indirect statement
• cum iuvenis esset — subordinate time/circumstance clause inside that indirect statement
• ad forum — motion toward
• saepe — often
• fabas et hordeum emptum — purpose: to buy beans and barley

So the core pattern is:

• [Main verb of saying] + [accusative subject] + [infinitive]

with extra details inserted into that indirect statement.