Discipuli in bibliotheca facilius discunt, quia ibi tacent.

Because discipuli is nominative plural. It is the subject of discunt, so it means the students.

The singular would be discipulus = student.
The plural is discipuli = students.

So:

• discipulus discit = the student learns
• discipuli discunt = the students learn

Because in can take two different cases depending on the meaning:

• in + ablative = in / on a place, showing location
• in + accusative = into / onto a place, showing motion toward

Here the sentence means the students learn in the library, not into the library, so Latin uses the ablative:

• in bibliotheca = in the library

If it were motion toward the library, it would be:

• in bibliothecam = into the library

It is ablative singular.

The preposition in takes the ablative when it means location, and bibliotheca is a first-declension noun. So in this sentence:

• bibliotheca = ablative singular
• in bibliotheca = in the library

Facilius is a comparative adverb meaning more easily.

It comes from facile = easily.
So:

• facile = easily
• facilius = more easily

It modifies the verb discunt, telling us how the students learn.

So discipuli facilius discunt means the students learn more easily.

That is a very common question. Comparative adverbs in Latin often look like the neuter singular accusative form of the comparative adjective.

So from facilior, facilius = easier, the adverb is:

• facilius = more easily

Even though it looks like an adjective form, here it is functioning as an adverb, modifying discunt.

The ending -unt tells you that the verb is:

• present tense
• third person plural
• active

So discunt means they learn.

Its dictionary form is disco, discere = to learn.

Because Latin verbs include the subject in the ending, Latin does not need a separate word for they here.

Because Latin usually does not need to state the subject pronoun if the verb ending already makes it clear.

Tacent means they are silent or they keep quiet. The -ent ending already tells us the subject is they.

In this sentence, that implied they naturally refers back to discipuli.

So Latin can simply say:

• quia ibi tacent = because they are silent there

without adding a separate word for they.

Tacent comes from taceo, tacere, which means to be silent, to be quiet, or to keep silent.

So tacent means:

• they are silent
• they keep quiet

In this sentence, it explains why the students learn more easily.

They are related, but they do different jobs.

• in bibliotheca means in the library
• ibi means there

So in bibliotheca names the place directly, while ibi refers back to that place.

The sentence is basically:

• Students learn more easily in the library, because they are quiet there.

Latin often uses a word like ibi to refer back to a place already mentioned.

Quia means because.

It introduces a clause giving the reason:

• quia ibi tacent = because they are silent there

So the structure is:

• main idea: Discipuli in bibliotheca facilius discunt
• reason: quia ibi tacent

Latin word order is more flexible than English because the endings show how words function.

English relies heavily on word order:

• The students learn in the library

Latin can move words around more freely because:

• discipuli shows the subject
• discunt shows the verb and plural subject
• bibliotheca with in shows location

So this sentence is perfectly natural Latin even if the order does not exactly match English.

Not in a careful grammatical translation here.

Facilius is an adverb, so it should be translated with an adverb in English:

• more easily

If you say easier, that is an adjective in English, and adjectives do not correctly modify verbs.

So:

• correct: Students learn more easily
• less accurate: Students learn easier

Yes, literally that is very close.

Word for word:

• quia = because
• ibi = there
• tacent = they are silent

So a very literal rendering is:

• because there they are silent

But in natural English, we would usually say:

• because they are silent there
• or because they keep quiet there

Yes.

The explicit subject discipuli is given with discunt, and in the quia clause the subject is only implied in tacent. That implied subject is understood to be the same group: the students.

So the sentence means:

• The students learn more easily in the library, because the students are silent there.

Latin does not repeat discipuli because it is already clear.