Magistra dicit se verba difficilia iterum interpretari velle.

Because this sentence uses an indirect statement after dicit (says).

In Latin, after a verb of saying, thinking, knowing, hearing, and so on, the subject of the reported statement usually goes into the accusative, and the verb goes into an infinitive. So instead of something like she says that she wants..., Latin says:

• dicit = she says
• se ... velle = that she wants ...

Here se is the reflexive pronoun, and it refers back to the subject of the main verb, magistra. So:

• Magistra dicit se ... velle = The teacher says that she wants ...

If Latin used eam instead, that would usually mean the teacher says that another woman/girl wants ..., not herself.

The sentence breaks down like this:

• Magistra = the teacher
• dicit = says
• se ... velle = that she wants ...
• verba difficilia = difficult words
• iterum = again
• interpretari = to explain / interpret

So the grammar is:

• main clause: Magistra dicit
• indirect statement: se ... velle
• inside that, interpretari depends on velle

In other words:

• The teacher says
• that she wants
• to interpret the difficult words again

Because in Latin indirect statement, the verb of the reported statement is usually an infinitive.

English often uses that + a normal verb:

• The teacher says that she wants...

Latin usually uses:

• dicit se ... velle

Here velle is the infinitive to want, but in this construction it functions as the main verb of the reported statement.

So se verba difficilia iterum interpretari velle literally means something like:

• her to want to interpret the difficult words again

That sounds strange in English, but it is normal Latin indirect statement.

Because velle means to want, and to want naturally takes another verb: to want to do something.

So:

• velle = to want
• interpretari = to interpret / explain

Together:

• interpretari velle = to want to interpret

This is similar to English:

• She wants to explain
• She wants to interpret

So velle is the infinitive used for the indirect statement, and interpretari is the infinitive that completes the meaning of velle.

Because interpretari is a deponent verb.

Deponent verbs look passive in form, but have an active meaning. So:

• interpretor = I interpret / explain
• interpretari = to interpret / explain

Even though interpretari looks like a passive infinitive to an English-speaking learner, it is not passive in meaning here.

So in this sentence it means:

• to interpret
• not to be interpreted

Verba difficilia is accusative plural neuter.

Why? Because it is the direct object of interpretari.

• verba = words
• difficilia = difficult

Since the teacher wants to interpret the difficult words, those words are the thing being interpreted, so they go in the accusative.

You can see the agreement:

• verba = neuter plural accusative (or nominative)
• difficilia = neuter plural accusative (agreeing with verba)

Because se is a reflexive pronoun, and in this kind of construction it normally refers back to the subject of the main clause.

Here the subject of the main clause is:

• Magistra

So:

• Magistra dicit se ... velle = The teacher says that she herself wants ...

This is one of the most important uses of se in Latin. It often points back to the subject of the main verb.

Yes.

• se = herself, referring back to magistra
• eam = her, meaning some other female person

So compare:

• Magistra dicit se verba difficilia iterum interpretari velle.
  = The teacher says that she herself wants to interpret the difficult words again.

• Magistra dicit eam verba difficilia iterum interpretari velle.
  = The teacher says that another woman/girl wants to interpret the difficult words again.

This is a very important distinction in Latin.

Because Latin usually does not use a word like English that in this kind of sentence.

English says:

• The teacher says that she wants...

Latin usually uses the accusative-and-infinitive construction instead:

• Magistra dicit se ... velle

So the idea of that is built into the grammar of se ... velle, rather than being expressed by a separate word.

Interpretari is a present infinitive.

In indirect statement, the tense of the infinitive shows time relative to the main verb, not necessarily absolute time in English.

A present infinitive usually shows action happening at the same time as the main verb.

So:

• dicit ... velle = she says that she wants
• interpretari = to interpret at that same general time

The sentence presents her desire as current at the time of speaking.

Velle is the present infinitive of volo.

In indirect statement, the present infinitive usually represents a verb that is simultaneous with the main verb.

So:

• dicit se ... velle = she says that she wants ...

If Latin wanted to show earlier or later time inside the indirect statement, it could use a different infinitive form. But here the present infinitive gives the natural meaning: at the time she says it, she wants it.

Iterum is an adverb meaning again.

It goes with the action interpretari:

• iterum interpretari = to interpret again

Latin word order is more flexible than English word order, so iterum can often move around without changing the basic meaning very much. Here it is placed right before interpretari, which makes its connection very clear.

Because magistra is the subject of the main verb dicit.

• magistra = nominative singular, the teacher
• dicit = says

So magistra is the person doing the saying.

Inside the indirect statement, however, the subject changes form:

• se is accusative, because subjects of indirect statement are put in the accusative

That is why the sentence has:

• Magistra for the main subject
• se for the subject of the reported idea

That depends on context.

The verb interpretor, interpretari can mean things like:

• interpret
• explain
• expound
• sometimes translate

With verba difficilia, a natural sense is often:

• explain difficult words
• interpret difficult words

If the broader context is language learning or glossing vocabulary, explain may sound most natural in English. If the context is literary or analytical, interpret may fit better.

Yes. Latin word order is flexible because the endings show grammatical function.

For example, these would still express basically the same idea:

• Magistra se verba difficilia iterum interpretari velle dicit.
• Se verba difficilia iterum interpretari velle magistra dicit.

However, the original order is clear and natural:

• Magistra dicit se verba difficilia iterum interpretari velle.

It starts with the teacher, gives the main verb dicit, and then gives the whole reported statement.

The biggest things are:

1. Indirect statement
   Latin uses accusative + infinitive after dicit, not that

   • finite verb.

2. Reflexive pronoun
   se refers back to magistra, not to some other woman.

3. Deponent verb
   interpretari looks passive but means something active: to interpret / explain.

4. Two infinitives in a row
   velle interpretari simply means to want to interpret.

5. Case endings matter more than word order
   magistra is nominative, se and verba difficilia are accusative, and those endings tell you how the sentence works.