Bona consuetudo discipulum studiosiorem facit.

Because it modifies consuetudo, and consuetudo is a feminine noun.

In Latin, adjectives must agree with the nouns they describe in:

• gender
• number
• case

So:

• bona = feminine nominative singular
• consuetudo = feminine nominative singular

That is why Latin uses bona, not bonus or bonum.

Consuetudo is nominative singular, and it is the subject of the sentence.

It is the thing doing the action of facit.

So the basic structure is:

• bona consuetudo = the subject
• facit = the verb
• discipulum studiosiorem = what the subject causes

Even though consuetudo ends in -o, it is not a verb form here; it is a noun.

Because it is the direct object of facit.

The verb facit here means makes, and the person being made into something is put in the accusative.

So:

• discipulus = a student
• discipulum = the student (as direct object)

The sentence is saying that a good habit makes the student something.

Because it goes with discipulum and describes what the student is made into.

This is a very common Latin pattern:

• facere + accusative object + predicate accusative/predicate adjective

So here:

• discipulum = the student
• studiosiorem = more studious

Together they mean:

• makes the student more studious

Since studiosiorem refers to discipulum, it matches it in:

• case: accusative
• number: singular
• gender: masculine

Studiosiorem is the masculine/feminine accusative singular comparative form of studiosus, -a, -um.

The forms are:

• positive: studiosus = studious, eager
• comparative: studiosior = more studious
• accusative singular masculine/feminine: studiosiorem

Because it agrees with discipulum (masculine accusative singular), Latin uses studiosiorem.

Because the sentence does not explicitly say what the student is being compared to.

Latin comparatives do not always need quam. A comparative can simply mean:

• more X
• rather X
• X-er than before

So studiosiorem facit means:

• makes him more studious
• that is, more studious than he was previously

If Latin wanted to state the second thing in the comparison, then quam or another comparison structure could appear.

Here facit means makes.

The verb is from facio, facere, which can mean:

• do
• make
• cause

In this sentence it has a causative sense:

• bona consuetudo discipulum studiosiorem facit
• a good habit makes the student more studious

So this is not just does; it is specifically causes to become.

Facit is:

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

from facio, facere.

So it means:

• he/she/it makes
• in this sentence, it makes

The subject is bona consuetudo, so facit means a good habit makes.

Yes. Consuetudo is a third-declension noun.

Its dictionary form is:

• consuetudo, consuetudinis f.

A common beginner mistake is to think that a nominative ending tells you the declension by itself. But in Latin, that is not always safe.

For example:

• consuetudo ends in -o
• but its genitive is consuetudinis
• that shows it belongs to the third declension

Because Latin has no articles.

So bona consuetudo can mean:

• a good habit
• the good habit
• sometimes even good habit in a general sense

Which one is best depends on context and translation style.

English must choose an article, but Latin does not need one.

Yes. Latin word order is much freer than English word order because the endings show the grammatical roles.

So the same basic meaning could appear in other orders, such as:

• Discipulum bona consuetudo studiosiorem facit.
• Bona discipulum consuetudo studiosiorem facit.
  (less natural for a beginner, but still understandable)

The order in your sentence is straightforward:

• subject first: bona consuetudo
• object next: discipulum
• predicate adjective next: studiosiorem
• verb last: facit

That final-position verb is especially common in Latin.

Because it is not simply describing which student. It is describing what the student becomes as a result of the action.

Compare:

• discipulum studiosum video = I see the studious student
  Here studiosum is just an ordinary descriptive adjective.

But:

• discipulum studiosiorem facit = it makes the student more studious
  Here studiosiorem is a predicate adjective after a verb of making.

So in your sentence, studiosiorem is part of the result of facit, not just a label attached to discipulum.

Consuetudo can mean several related things, including:

• habit
• custom
• usual practice
• way of behaving

Which English word is best depends on context.

In a sentence like this one, habit is often the most natural translation, because the idea is that repeated good practice improves the student. But custom or good practice can also fit in some contexts.