Frater invidus querelam facit, quod soror laudatur.

Because frater is the subject of the main clause. It is the person doing the action of facit.

• frater = the brother
• nominative singular of a 3rd-declension noun

So Frater invidus querelam facit means The envious brother makes a complaint / complains.

Invidus is an adjective modifying frater, so it has to agree with it in:

• case: nominative
• number: singular
• gender: masculine

So:

• frater = masculine nominative singular
• invidus = masculine nominative singular

This agreement tells you that invidus describes frater.

In Latin, adjective placement is much freer than in English. Both frater invidus and invidus frater can mean the envious brother.

Putting the adjective after the noun is very normal Latin word order. It does not change the basic meaning here.

Literally, it means makes a complaint:

• querelam = complaint
• facit = makes / does

But in natural English, this is often better translated as:

• complains
• makes a complaint

So this is a common Latin way of expressing an action by using facere with a noun.

Because it is the direct object of facit.

The verb facit is active, and it takes an object answering the question what does he make?

• He makes a complaint
• therefore querelam is accusative singular

This is the accusative form of querela, a 1st-declension noun.

Facit is:

• 3rd person singular
• present tense
• active voice
• indicative mood

from the verb facere = to make / do

So facit means he/she/it makes or does.
Here, with frater as subject, it means the brother makes.

Here quod is a conjunction meaning because.

It introduces the reason for the complaint:

• Frater invidus querelam facit = the envious brother complains
• quod soror laudatur = because his sister is being praised

So the whole sentence gives both the action and the reason for it.

Yes. Quod can have several uses in Latin. For example, it can be:

• a relative pronoun: which
• a conjunction: because, that, sometimes the fact that

In this sentence, it is clearly a conjunction, because it introduces a clause explaining why the brother complains.

Because soror is the subject of the subordinate clause:

• soror laudatur = the sister is praised

Even though she is receiving the action, she is still nominative, because in a passive sentence the receiver of the action becomes the grammatical subject.

Laudatur is:

• 3rd person singular
• present tense
• passive voice
• indicative mood

from laudare = to praise

So laudatur means:

• is praised
• is being praised

Both are acceptable translations in English, depending on context.

Because the sentence is focused on the sister as the one receiving praise, not on the person doing the praising.

• active: aliquis sororem laudat = someone praises the sister
• passive: soror laudatur = the sister is praised

Latin uses the passive here for exactly the same reason English does.

The main clause is:

• Frater invidus querelam facit

The subordinate clause begins with quod:

• quod soror laudatur

So the structure is:

• main statement: the envious brother complains
• reason clause: because the sister is praised

The word quod is your signal that a dependent clause is starting.

It can often be translated as either envious or jealous, depending on context. In many learning sentences, envious is the safer basic meaning.

So frater invidus suggests that the brother is upset because someone else, here his sister, is receiving praise.

The word order is meaningful, but the grammar mostly comes from the endings.

A very literal order is:

• Brother envious complaint makes, because sister is praised

Natural English would be:

• The envious brother complains because his sister is praised.

Latin can move words around more freely than English because case endings show each word’s role. Even so, this sentence is fairly straightforward and readable in its given order.