Desiderium patris puellam tristem facit.

Yes:

• desiderium — nominative singular neuter of desiderium; the subject
• patris — genitive singular of pater; it depends on desiderium
• puellam — accusative singular of puella; the direct object
• tristem — accusative singular feminine of tristis; an adjective agreeing with puellam
• facit — 3rd person singular present active indicative of facio; makes

So the basic structure is:

desiderium patris = the father’s desire/longing
puellam tristem facit = makes the girl sad

Because desiderium is a neuter noun.

In the 2nd declension, neuter nouns have the same form for nominative singular and accusative singular. So desiderium can be either nominative or accusative in form.

Here it is nominative because it is the thing doing the action: it makes the girl sad.

This is a very common point for learners, because -um often looks accusative at first, but with neuter nouns it can also be nominative.

Patris is genitive singular of pater.

It goes with desiderium and shows a relationship such as of the father. So desiderium patris means something like the father’s desire/longing.

A native English speaker often expects possession to be shown only with ’s, but Latin usually uses the genitive case instead.

Because Latin uses this pattern with facio:

subject + object in the accusative + adjective agreeing with that object + facit

So:

• puellam = the girl, the direct object
• tristem = sad, describing the girl as the result

In other words, tristem is not a separate object. It is an adjective telling you what the girl is made to be.

English does the same thing:

makes the girl sad

Here sad describes the girl, not the subject.

Because tristem does not describe the subject desiderium. It describes puellam, the direct object.

The sentence does not mean that the desire is sad. It means that the desire makes the girl sad.

Since puellam is accusative singular feminine, tristem must also be accusative singular feminine to agree with it.

You can tell from agreement.

• puellam is feminine accusative singular
• tristem is feminine accusative singular

So they match.

But desiderium is neuter singular. If tristis were describing desiderium, you would expect the neuter form triste, not tristem.

So the form of the adjective tells you that it belongs with puellam.

Facit is from facio, which can mean do, make, or cause depending on context.

In this sentence it means makes in the sense of causes someone to be a certain way.

So:

puellam tristem facit = it makes the girl sad

That is a very common Latin construction with facio.

Because Latin does not have articles like English the and a/an.

So Latin often says simply:

• pater where English might say the father or a father
• puella where English might say the girl or a girl

The translator supplies the or a from context. In this sentence, English naturally uses the.

The word order is less fixed in Latin than in English because the case endings show each word’s job.

So this sentence is arranged naturally as:

• desiderium patris first
• puellam tristem next
• facit at the end

But Latin could move the words around and still keep the same basic meaning, because:

• desiderium is still nominative
• patris is still genitive
• puellam is still accusative
• tristem still agrees with puellam

Changing the order would mostly change emphasis, not the core grammar.

The pattern is:

subject + genitive dependent on the subject noun + direct object + predicate adjective with the object + verb

More simply, you can think of it as:

X makes Y Z

where:

• X = desiderium patris
• Y = puellam
• Z = tristem

So the sentence works exactly like English The father’s desire makes the girl sad, even though Latin shows the relationships mostly by endings rather than by word order.