Duodecim paginae huic capitulo sunt, et magistra duodecim versus tantum hodie legendos dat.

Latin very often expresses possession with sum plus the dative.

So instead of saying:

• This chapter has twelve pages

Latin says something closer to:

• Twelve pages are to/for this chapter

That is why you get:

• paginae ... sunt = pages ... are
• huic capitulo = for this chapter / to this chapter

This is a very common Latin pattern, and English speakers often need time to get used to it.

Because paginae is the subject of sunt.

In this clause:

• Duodecim paginae huic capitulo sunt

the thing that are is twelve pages, so paginae must be nominative plural.

Its form is:

• pagina = singular nominative
• paginae = plural nominative

So duodecim paginae means twelve pages as the subject.

They are in the dative because of the Latin possession pattern with sum.

• huic = dative singular of hic, haec, hoc = this
• capitulo = dative singular of capitulum = chapter

Together, huic capitulo means to/for this chapter.

A native English speaker may expect this chapter to be the subject, but in Latin it is not the subject here. The subject is paginae.

Because duodecim is one of the Latin numerals that is normally indeclinable.

That means its form stays the same no matter what noun it goes with.

So Latin can say:

• duodecim paginae
• duodecim versus

with the same form duodecim each time.

This is normal for numbers like eleven through seventeen.

Here versus is accusative plural, because it is the direct object of dat.

• magistra ... dat = the teacher gives
• What does she give? duodecim versus tantum hodie legendos

So versus is the thing being given/assigned.

The noun is versus, -us (masculine, 4th declension). In many textbooks without macrons, the nominative plural and accusative plural can look the same in writing:

• nominative plural: versūs
• accusative plural: versūs/versus depending on how the text marks long vowels

Without macrons, you just use syntax to tell the case. Here it must be accusative because it is the object of dat.

legendos is the gerundive of lego (read), agreeing with versus.

It is:

• masculine
• plural
• accusative

because it modifies versus.

So:

• versus legendos = lines to be read / lines for reading

This is a very common Latin way to express something that is to be done.

Here the idea is that the teacher is giving or assigning twelve lines to be read.

Because Latin is not saying the teacher gives to read with an infinitive. Instead, it is describing the lines as to-be-read lines.

Compare the structure:

• versus legendos dat = she gives lines to be read
• not she gives to read lines

The gerundive lets Latin attach the idea of necessity, suitability, or assignment directly to the noun.

So legendos agrees with versus, while legere would be an infinitive and would work quite differently.

tantum means only here, and it limits the quantity: only twelve lines.

Latin word order is much freer than English word order, so tantum can be placed near the phrase it limits rather than always directly before it.

So:

• duodecim versus tantum

means:

• only twelve lines

An English speaker may expect tantum to come before the whole phrase, but Latin often places emphasis words flexibly.

Because Latin word order is flexible and often arranged for emphasis or style, not because of strict fixed positions.

In the second clause:

• et magistra duodecim versus tantum hodie legendos dat

hodie naturally sits close to the verbal idea: the teacher gives the assignment today.

Latin could move hodie elsewhere and still be grammatical. Its position here is perfectly normal.

It agrees with versus, not with magistra.

You can tell from the form:

• versus is masculine plural accusative
• legendos is also masculine plural accusative

Meanwhile:

• magistra is feminine singular nominative

So legendos cannot be modifying magistra. It must go with versus.

That gives the phrase:

• duodecim versus ... legendos = twelve lines ... to be read

Yes. Latin often leaves out the subject pronoun, and sometimes even the noun subject, if the verb already makes it clear enough.

Since dat means she gives, Latin could have omitted magistra if the context already made the subject obvious.

But including magistra makes the sentence clearer and more explicit:

• the teacher gives the assignment

So magistra is not required by the verb form, but it is useful for clarity or emphasis.