Magister discipulis dicit: “Extra scholam currere vobis nunc non licet.”

Magister is nominative singular because it is the subject of dicit.

So the basic structure is:

magister ... dicit = the teacher says

Latin often marks the job a word is doing by its ending, so magister here is the one doing the speaking.

Because dicere can take the person addressed in the dative:

alicui dicere = to say to someone

So:

magister discipulis dicit = the teacher says to the students

A native English speaker may expect something more like tells the students, but Latin commonly uses dicere with a dative for say to.

Latin can use direct speech just like English:

The teacher says: ...

That is what is happening here. The words after the colon are presented as the teacher’s exact words.

Because it is direct speech, the teacher speaks directly to the students, so inside the quotation we get vobis = to you.

Because extra is a preposition that takes the accusative.

So:

extra scholam = outside the school

This is just something you learn with the vocabulary: extra + accusative.

It means outside the school or outside school.

A useful distinction:

• extra scholam emphasizes being outside the school area
• ex schola would more strongly suggest movement out of the school

So in this sentence, extra scholam currere means to run outside the school / outside school, not specifically to run out of the school building.

Because after licet, Latin normally uses an infinitive to express the action that is permitted or not permitted.

So:

currere licet = it is permitted to run
currere non licet = it is not permitted to run

If Latin used curritis, that would mean you run / are running, which is a different kind of statement.

Licet is an impersonal verb meaning it is permitted, it is allowed, or more naturally in English, one may / you may.

Its common pattern is:

alicui + infinitive + licet

That means:

• the person affected goes in the dative
• the action goes in the infinitive

So here:

• vobis = for you / to you
• currere = to run

Together:

vobis currere non licet = you are not allowed to run

Because licet takes the person who is allowed or not allowed to do something in the dative.

So:

mihi licet = I am allowed
tibi licet = you are allowed
vobis licet = you all are allowed

In this sentence:

vobis ... non licet = it is not permitted for you

Yes, they both refer to the students, but they belong to different parts of the sentence.

• discipulis goes with dicit: the teacher says to the students
• vobis goes with licet inside the quotation: it is not permitted for you

So they are not duplicates in a grammatical sense. One is part of the reporting clause, and the other is part of the teacher’s actual words.

English does the same kind of thing:

The teacher says to the students, You are not allowed...

Yes, it could be omitted if the meaning were obvious from context, but keeping it makes the sentence more explicit.

Without vobis, currere non licet would mean something like running is not allowed or it is not allowed to run.

With vobis, the teacher clearly directs the rule to you.

No, because licet is impersonal.

That means it does not have a normal personal subject like I, you, or they. It stays in the third person singular form:

licet = literally it is permitted

The it is only a dummy subject, like in English it is raining. So licet does not change to match vobis.

Because non normally goes before the word or phrase it negates.

Here it negates licet:

non licet = it is not permitted

That is the standard and most natural way to say not allowed.

Nunc means now, and it modifies the whole permission statement.

So the idea is:

At this moment / for now, you are not allowed to run outside the school.

It does not really belong only to currere or only to extra scholam; it applies to the rule as a whole.

It is not unusual for Latin. Latin word order is much freer than English word order.

A very literal arrangement here is:

Outside the school to run for you now not is-permitted.

Latin can do this because the endings show the grammar clearly. The order used here puts the forbidden action, extra scholam currere, near the front, which gives it a little emphasis.

A different order such as Vobis nunc extra scholam currere non licet would also be perfectly understandable.

A very useful pattern is:

alicui + infinitive + licet / non licet

For example:

• mihi intrare licet = I am allowed to enter
• tibi abire non licet = you are not allowed to leave
• vobis currere non licet = you are not allowed to run

If you remember that pattern, the heart of this sentence becomes much easier to understand.