Learn Hardcore Latin: Luna, quae nocte lucet, puellam quietam facit. - The moon, which shines at night, makes the girl calm.

Luna comes from the noun lūna, lūnae (f.) – “moon.”
First-declension singular endings include: -a (nom.), -ae (gen.), -ae (dat.), -am (acc.), -ā (abl.).
Since it ends in -a here and agrees with the 3rd person singular verb facit (“makes”), luna is the subject:
Luna … facit = “The moon … makes.”

What exactly is quae nocte lucet doing in the sentence?

Quae nocte lucet is a relative clause that describes luna.

Quae refers back to luna and means “which”.
Nocte = “at night.”
Lucet = “shines.”
So quae nocte lucet = “which shines at night”, giving extra information about the moon.

The whole structure is:
Luna, quae nocte lucet, puellam quietam facit.
= “The moon, which shines at night, makes the girl calm.”

Why is the relative pronoun quae and not qui or quod?

Relative pronouns in Latin must:

Agree in gender and number with the noun they refer to (called the “antecedent”), and
Take their case from their role in the relative clause.

Here:

Antecedent: luna – feminine, singular.
So the relative pronoun must also be feminine singular → quae.
In the clause quae nocte lucet, quae is the subject of lucet, so it is in the nominative.

That’s why you get quae (fem. nom. sg.), not qui (masc.) or quod (neut.).

What case is nocte, and what does it mean here?

Nocte is ablative singular of nox, noctis (f.) – “night.”

Nominative: nox
Genitive: noctis
Ablative singular: nocte

In this sentence it is an ablative of time when, meaning “at night.”
So quae nocte lucet = “which shines at night.”

There is no word for “at” before nocte. How do we know it means “at night”?

Latin often expresses time with the bare ablative case, without a preposition:

nocte = “at night”
diē = “by day / in the day”
tertiā hōrā = “at the third hour”

This use is traditionally called the ablative of time when. English needs a preposition (“at,” “in,” “on”), but Latin usually just uses the ablative form alone.

What does lucet mean, and why doesn’t it take an object?

Lucet is the 3rd person singular present of lucēre – “to shine.”

lucet = “it shines” or “she shines.”
It is an intransitive verb here: it does not take a direct object.
The understood subject of lucet is quae (referring to luna).

So quae nocte lucet = “which shines at night,” not “which shines something.”

Why are puellam and quietam both in the accusative case?

Both words are in the accusative feminine singular because they form a direct object + object complement structure:

puellam (from puella, puellae): direct object of facit – “(makes) the girl.”
quietam (from quietus, -a, -um): predicate accusative / object complement – “(makes) the girl quiet/calm.”

Latin often uses verb + object (acc.) + adjective in the same case to mean “to make someone/something X”:

puellam quietam facit = “(she/it) makes the girl quiet.”

Since quietam describes the object, it “follows” the object’s case: accusative.

Why isn’t quietam in the nominative, since it describes the girl?

In Latin, adjectives that describe the subject are nominative, but adjectives that describe the object after certain verbs (like “make, call, consider”) match the object’s case.

Here:

Subject: luna (nominative).
Object: puellam (accusative).
Quietam describes puellam, not luna, so it must also be accusative.

This is called a predicate accusative or object complement:

Luna puellam quietam facit
“The moon makes the girl quiet.”

Is facit just “makes,” or does it have a special construction here?

Facit (“makes”) is used in a common Latin pattern:

Subject + facere + object (acc.) + predicate (acc.)

This means “to cause someone/something to be X.”

Luna – subject
puellam – object
quietam – predicate accusative / complement
facit – verb

Putting it together: Luna puellam quietam facit =
“The moon makes the girl calm / causes the girl to be calm.”

Why is the verb facit at the end of the sentence? Is that normal in Latin?

Yes, it is very normal. A common Latin word order is:

Subject – (modifiers) – Object – Verb

So:

Luna (subject)
quae nocte lucet (clause modifying luna)
puellam quietam (object + complement)
facit (verb)

The word order is fairly free in Latin because the endings show who is doing what, but putting the main verb at the end of the sentence is very typical prose style.

Could quietam come before puellam? Would that change the meaning?

You could say:

Luna, quae nocte lucet, quietam puellam facit.

The basic meaning would be the same: “The moon makes the girl quiet.”

However:

Keeping the adjective next to its noun (puellam quietam) is clearer and more neutral.
Quietam puellam slightly emphasizes “quiet” more, but context would decide if that nuance is strong.

Latin allows this flexibility as long as case endings match and it’s clear which words belong together.

Do the commas around quae nocte lucet matter for the meaning, like in English?

They signal that the relative clause is non‑restrictive, giving extra information about luna, like English:

“The moon, which shines at night, …”

Without commas, luna quae nocte lucet could be read more restrictively: “the moon that shines at night,” as if distinguishing it from some other moon (which is rarely needed here, of course).

In classical Latin manuscripts, punctuation was much looser than in modern printed texts, but the idea of a non‑essential descriptive clause (our “which shines at night”) is the same.