Puella rogat cur fermentum massae necessarium sit; mater respondet fermentum panem molliorem facere.

Because cur introduces an indirect question after rogat.

• Direct question: Cur fermentum massae necessarium est?
• Indirect question: Puella rogat cur fermentum massae necessarium sit.

In Latin, indirect questions normally take the subjunctive, so est becomes sit.

It is specifically the present subjunctive because:

• the main verb rogat is present, and
• the necessity is happening at the same time as the asking.

So sit is not translating a different meaning here; it is mostly a grammatical signal that this is an indirect question.

Here massae is best understood as dative singular, meaning for the dough.

So:

• fermentum = yeast / leaven
• massae = for the dough
• necessarium = necessary

Together: yeast is necessary for the dough.

A learner may notice that massae could also look like a genitive singular form, because first-declension genitive singular and dative singular are identical. But in this sentence, the sense is dative, since necessarius often goes with the dative of the thing or person for which something is necessary.

Because it agrees with fermentum, which is neuter singular.

• fermentum = neuter singular
• therefore necessarium must also be neuter singular

Latin adjectives agree with the nouns they describe in:

• gender
• number
• case

So necessarium means necessary, and its ending matches fermentum.

Because after a verb like respondet, Latin often uses an indirect statement, and the normal construction for an indirect statement is:

accusative subject + infinitive

So instead of saying directly:

• Fermentum panem molliorem facit
  Yeast makes bread softer

Latin reports it indirectly as:

• mater respondet fermentum panem molliorem facere
  the mother answers that yeast makes bread softer

So facere is the infinitive because the whole clause is being reported, not stated directly.

Grammatically, it is accusative, because it is the subject of the infinitive facere in an indirect statement.

That may seem strange at first, because in English the subject would stay in the normal subject form. But Latin indirect statement works differently:

• direct statement: fermentum ... facit
• indirect statement: fermentum ... facere

In this sentence, fermentum looks the same in nominative and accusative because it is a neuter singular second-declension noun. Neuter nominative and accusative singular are identical.

So the form looks nominative, but its function here is accusative.

Because panem is the direct object of facere.

The idea is:

• fermentum = yeast
• facere = to make
• panem = bread

So literally: yeast to make bread softer.

Even inside an indirect statement, the infinitive facere still takes its normal object, and that object is in the accusative.

Because molliorem agrees with panem as an object complement.

With verbs like facere, Latin often uses this pattern:

object + adjective in agreement with the object

So:

• panem = bread
• molliorem = softer

Together they mean the bread softer.

This is similar to English make the bread softer. Latin does not need a separate to be here. The adjective simply agrees with the object in case, number, and gender.

So molliorem is accusative singular masculine because it matches panem.

Because molliorem is the comparative form, meaning softer.

• mollis = soft
• mollior, mollius = softer

So panem molliorem facere means to make the bread softer, not just to make the bread soft.

The comparative makes good sense here: yeast makes bread softer than it would otherwise be.

Not exactly. Latin often does not use esse after verbs like facere when an object complement is present.

So:

• panem molliorem facere = to make the bread softer

Latin does not need to say:

• panem molliorem esse facere

That would be wrong. The construction is already complete with:

• object: panem
• complement: molliorem
• verb: facere

So the meaning includes the idea of becoming softer, but Latin expresses that directly through facere + object + complement.

Latin word order is fairly flexible, because the endings show the grammatical relationships.

This sentence is arranged in a natural and clear way:

• Puella rogat cur...
• mater respondet...

and then each clause puts its key idea in a sensible place.

For example:

• cur comes early, which is normal for a question word.
• facere comes at the end of the reported statement, which is also very common in Latin.

A different order could still be grammatical if the endings remain the same. Latin word order often reflects:

• emphasis
• style
• rhythm

So the given order is normal, but not the only possible one.