Nunc magister pacem amat et discipuli eum laudant.

Because pacem is the accusative singular form of pax.

In this sentence, peace is the direct object of amat (loves), so Latin puts it in the accusative case:

• pax = nominative, peace as subject
• pacem = accusative, peace as direct object

So magister pacem amat means the teacher loves peace, with pacem showing what is being loved.

Because magister is the subject of the verb amat, so it stays in the nominative singular.

Latin changes nouns depending on their job in the sentence:

• magister = subject, so nominative
• pacem = direct object, so accusative

English mostly shows this with word order, but Latin often shows it with endings.

Nunc means now.

It is an adverb, so it does not have case or number. It simply adds the idea of time to the sentence. Latin word order is flexible, so nunc can often appear in different places, though putting it first is very natural for emphasis:

• Nunc magister pacem amat... = Now the teacher loves peace...

Because discipuli means students or pupils, not student.

It is the nominative plural form of discipulus:

• discipulus = student
• discipuli = students

Since it is plural, the verb also has to be plural, which is why the sentence has laudant and not laudat.

Because discipuli is plural.

Latin verbs change to match their subject:

• laudat = he/she/it praises
• laudant = they praise

So:

• discipuli eum laudant = the students praise him

The plural ending -nt tells you the subject is they.

Eum means him, and here it refers back to magister.

So the sentence means that the students praise the teacher. Latin often uses a pronoun like this to avoid repeating the noun:

• magister = the teacher
• eum = him

Grammatically, eum is accusative singular masculine, because it is the direct object of laudant and refers to a masculine singular person.

Because eum is the accusative form, while is is the nominative form.

The pronoun is, ea, id changes by case:

• is = he
• eum = him

Since him is the object of laudant, Latin needs the accusative form eum.

You know mainly from the endings, not just from the position.

In this sentence:

• magister is nominative singular, so it is the subject of amat
• pacem is accusative singular, so it is the object of amat
• discipuli is nominative plural, so it is the subject of laudant
• eum is accusative singular, so it is the object of laudant

So even if the word order changed, the endings would still tell you the basic roles.

Yes, often it could.

Latin word order is more flexible than English because endings show grammatical function. For example, versions like these could still mean essentially the same thing:

• Magister nunc pacem amat et discipuli eum laudant.
• Pacem nunc magister amat et discipuli eum laudant.

However, changing the order can change emphasis. Putting a word earlier or later may make it stand out more.

Classical Latin has no definite article like English the and no indefinite article like a/an.

So:

• magister can mean the teacher or a teacher
• discipuli can mean the students or students

You decide from the context which English article fits best.

Because Latin verb endings already include the subject.

For example:

• amat = he/she/it loves
• laudant = they praise

So Latin often does not need subject pronouns like he or they unless the speaker wants extra emphasis or contrast.

Yes. Both are second-declension masculine nouns.

Their dictionary forms are:

• magister, magistri = teacher
• discipulus, discipuli = student

In this sentence you see:

• magister = nominative singular
• discipuli = nominative plural

Even though both are second declension, they do not look exactly the same in every form, so it is important to learn each noun’s principal forms.

They are both present tense.

• amat = loves / is loving
• laudant = praise / are praising

The sentence describes what is happening now, and nunc reinforces that idea.