Magistra illi sententiam iterum explicat.

Because magistra is in the nominative singular, which is the case normally used for the subject.

A learner can also spot this from the verb:

• explicat = he/she explains
• that is 3rd person singular
• so the subject should be one person

So magistra fits perfectly as the teacher or the female teacher as the subject.

Sententiam is accusative singular.

It is the direct object of explicat, because it is the thing being explained. In other words, the teacher explains the sentence.

You can recognize it as accusative singular because:

• the noun is sententia
• first-declension accusative singular usually ends in -am
• so sententiam = the sentence as a direct object

Here illi is most naturally dative singular, meaning to him, to her, or to that person.

It is the indirect object:

• magistra = the teacher
• sententiam = the sentence
• explicat = explains
• illi = to him / to her

So the structure is basically:

The teacher explains the sentence again to him/her.

Yes, illi can have several forms in Latin, which is why learners often pause at it.

It can be, for example:

• dative singular of ille = to him / to her / to it / to that person
• nominative masculine plural = those
• sometimes other meanings depending on context

But in this sentence, dative singular is the best reading because:

• explicat is singular, so illi is not likely to be a plural subject
• the sentence already has a clear subject, magistra
• the verb explicat works very naturally with a direct object plus an indirect object

So here illi is best understood as to him or to her.

Classical Latin usually has no definite article and no indefinite article.

So Latin often says simply:

• magistra instead of the teacher or a teacher
• sententiam instead of the sentence or a sentence

English has to choose the or a/an, but Latin usually leaves that to context.

That means magistra illi sententiam iterum explicat could be translated in slightly different ways depending on context:

• The teacher explains the sentence to him again
• A teacher explains a sentence to her again

Usually the broader context tells you which one is most natural.

Iterum is an adverb, and it means again.

It modifies the verb explicat, telling you how the action happens: the teacher explains it again.

Latin word order is more flexible than English word order, so iterum can often move around without changing the basic meaning. For example, these would all be possible in Latin:

• Magistra illi sententiam iterum explicat
• Magistra iterum illi sententiam explicat
• Iterum magistra illi sententiam explicat

The placement can create a slightly different emphasis, but the core meaning stays the same.

Latin often places the verb near the end of the sentence, although it does not have to.

So Magistra illi sententiam iterum explicat follows a very common Latin pattern:

• subject
• indirect object
• direct object
• adverb
• verb

But Latin is not as rigid as English. Because case endings show each word’s role, the sentence can often be rearranged for emphasis.

For example:

• Sententiam magistra illi iterum explicat
• Illi magistra sententiam iterum explicat

These still mean essentially the same thing, though the emphasis shifts.

Explicat is:

• present tense
• 3rd person singular
• active voice
• indicative mood

So it means he explains, she explains, or it explains.

In this sentence, because the subject is magistra, it means she explains.

So the full verbal idea is the teacher explains.

Because the ending of the verb already tells you the person and number.

With explicat, the ending -t shows:

• 3rd person
• singular

So Latin can simply say explicat and leave the subject implied if it wants.

Here, however, Latin includes magistra to make the subject explicit:

• explicat = she explains
• magistra explicat = the teacher explains

Latin often omits subject pronouns like she, he, or they unless they are needed for emphasis or clarity.

Yes. Magistra is a regular first-declension noun.

Its basic forms are:

• nominative singular: magistra
• genitive singular: magistrae

Even though many first-declension nouns are feminine, what matters grammatically is the declension pattern, not whether the noun refers to a person or a thing.

So in this sentence:

• magistra = nominative singular
• it is feminine in meaning
• and it is declined like a normal first-declension noun

Because the ending -am marks accusative singular for a first-declension noun.

Compare:

• sententia = nominative singular
• sententiam = accusative singular
• sententiae = nominative plural or genitive/dative singular, depending on context
• sententias = accusative plural

So sententiam means one sentence as the direct object, not sentences.

Very often, yes.

In a sentence like this, explicare can work as:

• something explained = direct object in the accusative
• person receiving the explanation = indirect object in the dative

So:

• sententiam = what is explained
• illi = to whom it is explained

This is very similar to English explain something to someone. Latin just marks those relationships with case endings instead of mostly relying on word order or prepositions.