Magistra discipulis explicat cur senatus et magistratus in urbe magni sint.

Because cur senatus et magistratus in urbe magni sint is an indirect question after explicat.

• cur = why
• explicat = she explains

So the sentence is not directly asking Why are the senate and the magistrates important? Instead, it says that the teacher explains why they are important.

In Latin, indirect questions normally use the subjunctive, so:

• direct question: cur ... magni sunt?
• indirect question: cur ... magni sint

That is why sint appears here.

Discipulis is dative plural.

It is dative because explicare can take the person to whom something is explained in the dative:

• magistra discipulis explicat = the teacher explains to the students

So:

• magistra = the teacher
• discipulis = to the students
• explicat = explains

A learner might first expect an accusative here, but Latin often uses the dative for the person receiving the explanation.

The subject is magistra.

• magistra is nominative singular feminine
• explicat is third person singular

So magistra explicat means the female teacher explains.

Latin often leaves subjects unstated because the verb ending already gives a clue, but here the subject is stated explicitly.

Here, yes: magistra is the feminine form meaning female teacher.

It corresponds to:

• magister = male teacher
• magistra = female teacher

The ending -a often signals a first-declension noun, and many first-declension nouns are feminine, though not every noun ending in -a is feminine in all contexts. In this sentence, magistra is definitely feminine.

Urbe is ablative singular because in with a location usually takes the ablative.

So:

• in urbe = in the city

This is a standard rule:

• in + ablative = in/on somewhere
• in + accusative = into/onto somewhere

Compare:

• in urbe = in the city
• in urbem = into the city

Magni is a predicate adjective agreeing with senatus et magistratus.

It means something like important or great here.

Because the subject of sint is plural overall, the adjective is also plural:

• magni sint = are important / may be important

Even though senatus can look singular in form, the full subject is senatus et magistratus, so the idea is plural, and magni must be plural too.

Because magnus would be singular masculine nominative, while magni is plural masculine nominative.

Here the adjective describes senatus et magistratus together, so it must be plural:

• magnus = important/great, singular
• magni = important/great, plural

Since the sentence is talking about more than one political institution or office-holder, Latin uses the plural form.

This is a very good question, because both forms are a little tricky.

Both senatus and magistratus are fourth-declension nouns, and in that declension the nominative singular and nominative plural can look the same.

So by form alone:

• senatus could be the senate or the senates
• magistratus could be the magistrate or the magistrates

In this sentence, the meaning normally understood is:

• senatus = the senate (singular)
• magistratus = the magistrates (plural)

So the phrase means the senate and the magistrates.

Context and meaning help you decide. A single senate and multiple magistrates make good sense in Roman political context.

They are fourth-declension masculine nouns.

• senatus, -us = senate
• magistratus, -us = magistrate / magistracy / magistrates, depending on context

This declension can be confusing for English-speaking learners because the -us ending may look like a second-declension singular nominative, but these are actually fourth-declension nouns.

Because classical Latin does not have a definite article like English the.

So:

• magistra can mean a teacher or the teacher
• senatus can mean the senate
• in urbe can mean in the city

You figure out whether English should use a or the from context.

That is very normal in Latin, even though it feels strange to English speakers.

Cur means why.

In this sentence it introduces an indirect question:

• cur senatus et magistratus in urbe magni sint
• why the senate and the magistrates are important in the city

So cur is not just a random conjunction; it signals the content of what is being explained.

Cur itself does not automatically force the subjunctive in every situation.

What matters here is that this is an indirect question. Indirect questions in Latin normally use the subjunctive.

So:

• direct: Cur senatus magnus est?
• indirect: Explicat cur senatus magnus sit.

If cur appears in a direct question, you would usually see the indicative if the sense calls for it. Here the subjunctive comes from the indirect-question construction.

A helpful breakdown is:

• Magistra = subject
• discipulis = indirect object
• explicat = main verb
• cur senatus et magistratus in urbe magni sint = clause giving what she explains

So the structure is:

The teacher explains to the students [why the senate and the magistrates are important in the city].

Seeing it in chunks often makes the whole sentence much easier to read.

Because the verb agrees with the subject, not with the indirect object.

Here:

• magistra = subject, singular
• discipulis = indirect object, plural

So the verb must be singular:

• magistra explicat = the teacher explains

The fact that the explanation is given to the students does not change the number of the verb.

Yes. Magnus has a broad range of meanings, including:

• great
• large
• important
• powerful

In this sentence, because it is about political institutions in the city, important is usually the best natural English choice. But the core Latin idea is something like great/significant.

Latin word order is much freer than English word order because Latin uses endings to show grammatical relationships.

English depends heavily on position:

• The teacher explains to the students...

Latin can move words around more easily because the forms tell you their jobs:

• magistra = nominative subject
• discipulis = dative
• urbe = ablative after in
• sint = plural subjunctive verb

So even though the order may feel unusual, the endings make the meaning clear. Latin authors also use word order for emphasis and style, not just grammar.

Not with the same meaning.

• cur means why
• quod often means because or that

This sentence is about explaining why something is true, so cur is the right word.

If you used quod, you would change the construction and probably the meaning. The sentence as written is specifically built around an indirect question: why are they important?

Most likely it refers to the magistrates, meaning the people who hold political office.

But magistratus can sometimes refer more abstractly to magistracy or public office.

In this sentence, because it is paired with senatus and translated naturally in context, learners will usually understand it as the magistrates. Context outside the sentence would confirm that.

Actually, the content being explained is expressed by the whole clause:

• cur senatus et magistratus in urbe magni sint

So instead of a simple noun object like rem or causam, Latin uses a clause: why the senate and the magistrates are important in the city.

That entire clause functions as what is being explained.

You can parse it like this:

• Magistra — nominative singular
• discipulis — dative plural
• senatus — nominative (singular in sense here, though the form can also be plural)
• magistratus — nominative plural in sense here, though the form can also be singular
• urbe — ablative singular
• magni — nominative plural masculine adjective
• explicat — 3rd person singular present indicative active
• sint — 3rd person plural present subjunctive active

This kind of full parsing is often the best way to get comfortable with a Latin sentence.

It would look like this:

Cur senatus et magistratus in urbe magni sunt?

That means:

Why are the senate and the magistrates important in the city?

Notice the change:

• indirect question: sint
• direct question: sunt

That contrast is one of the most useful things to learn from this sentence.