Mater dicit panem emendum esse, quia nihil in domo est.

It is an indirect statement built with an accusative + infinitive, and inside that indirect statement there is a passive periphrastic.

So:

• dicit = says
• after a verb of saying, Latin often reports the statement with accusative + infinitive
• panem emendum esse literally means bread to-be-bought to be

A more natural English rendering is:

• that bread must be bought
• or that it is necessary to buy bread

The key idea of gerundive + esse is necessity.

Because in Latin indirect statement, the subject of the infinitive goes into the accusative.

If this were a direct statement, Latin would say:

• Panis emendus est = The bread must be bought

But after dicit, that becomes:

• Mater dicit panem emendum esse = Mother says that the bread must be bought

So:

• direct statement: panis
• reported statement after dicit: panem

That shift from nominative to accusative is very common in Latin.

Because emendum has to agree with panem.

Panem is:

• masculine
• singular
• accusative

So the gerundive must also be:

• masculine
• singular
• accusative

That gives emendum.

If the noun were nominative, then you would get emendus:

• panis emendus est

Agreement is the reason for the ending.

Emendum is the gerundive of emo, emere.

The gerundive is a verbal adjective that often expresses necessity or something needing to be done.

So emendum means something like:

• needing to be bought
• to be bought

In this sentence, it works with esse:

• panem emendum esse = that bread needs to be bought

A learner may notice that the perfect participle of emo is emptus, but the gerundive is formed from the present stem, so it is emendus, not something based on empt-.

Because Latin indirect statement uses an infinitive, not a finite verb.

In a direct statement, you would have:

• Panis emendus est = The bread must be bought

When that statement is reported after dicit, the finite verb est changes to the infinitive esse:

• panem emendum esse

So esse is there because the whole reported idea is being expressed as an infinitive clause.

No. The sentence does not explicitly say who must buy it.

Latin can express the person obliged to do something with a dative of agent, especially in passive periphrastic constructions. For example, it could say something like mihi panis emendus est = I must buy bread.

But here there is no such dative. The sentence simply says that bread needs to be bought, without naming the responsible person.

In context, we may assume the household or someone present is expected to do it, but the Latin itself leaves that unstated.

Because Latin normally reports statements after verbs like say, think, know, and hear with accusative + infinitive, not with a word exactly equivalent to English that.

So English says:

• Mother says that bread must be bought

But Latin says:

• Mater dicit panem emendum esse

This is one of the most important differences between English and Latin syntax. English often uses that; Latin often uses the accusative-and-infinitive construction.

It is a causal clause introduced by quia, meaning because.

Breaking it down:

• quia = because
• nihil = nothing
• in domo = in the house / at home
• est = is

So the clause means:

• because there is nothing in the house
• or more naturally, because there is nothing at home

This clause gives the reason for the necessity expressed in panem emendum esse.

Nihil means nothing.

It is a common neuter pronoun used in an impersonal way. In this sentence it is the subject of est:

• nihil est = there is nothing

English often uses there is in such sentences, but Latin simply says nothing is.

So quia nihil in domo est literally is:

• because nothing is in the house

but in natural English:

• because there is nothing in the house

Both can relate to the idea of home, but they are not exactly the same.

• domi usually means at home
• in domo means more literally in the house

So nihil in domo est emphasizes that there is nothing in the house, nothing in the household stores.

A Latin author might use either expression depending on the nuance wanted, but in domo is perfectly normal here.

The word order is meaningful, but not as rigid as in English.

The sentence is:

• Mater dicit panem emendum esse, quia nihil in domo est.

A natural way to understand the structure is:

• Mater dicit = main verb
• panem emendum esse = reported statement
• quia nihil in domo est = reason

Latin can move words around more freely because the endings show their function. Even so, this order is clear and natural:

1. who is speaking
2. what she says
3. why she says it

So the order helps the flow, but the grammar depends mainly on the endings, not position alone.