Puella litteras matris iterum legit et dicit se unam litteram nondum intellegere.

Because Latin often uses litterae (plural) to mean a letter / an epistle. That is a normal idiom.

So:

• litterae / litteras = a written letter, correspondence
• littera / litteram = a single letter of the alphabet

That is why this sentence can have both:

• litteras matris = the mother’s letter
• unam litteram = one letter (one character, symbol, or individual written letter)

This is a very common point of confusion for English speakers.

Matris is the genitive singular of mater, meaning of the mother or the mother’s.

So litteras matris means the mother’s letter.

Latin often uses the genitive where English uses either:

• of
  • noun, or
• a possessive with ’s

Examples:

• liber pueri = the boy’s book
• vox magistri = the teacher’s voice
• litteras matris = the mother’s letter

Latin does not always need a possessive adjective where English does.

In English, we often say her mother’s letter or the letter of her mother. In Latin, matris by itself can be enough if the context already makes clear whose mother is meant.

So Latin is often more economical than English here. The relationship is shown by the genitive matris, and context supplies the rest.

Legit is the 3rd person singular form of legere, to read.

It can represent either:

• he/she reads (present), or
• he/she read (perfect)

Without macrons, the spelling is the same. With macrons, they would be distinguished in careful writing:

• legit = reads
• lēgit = read

In this sentence, context normally points to the present: the girl reads ... and says ...

Because Latin word order is much freer than English word order.

Iterum is an adverb meaning again, and adverbs can often move around without changing the basic meaning. Latin uses word order more for emphasis and style than for strict grammar.

So these would all be understandable Latin with slightly different feel or emphasis:

• Puella litteras matris iterum legit
• Puella iterum litteras matris legit
• Iterum puella litteras matris legit

The original order is perfectly natural.

After verbs of saying, thinking, knowing, perceiving, and similar verbs, Latin often uses indirect statement, also called the accusative and infinitive construction.

So instead of saying:

• she says that she does not yet understand ...

Latin says literally:

• she says herself not yet to understand ...

That is why you get:

• dicit = she says
• se = herself / that she
• intellegere = to understand

This is one of the most important Latin constructions to learn.

Because in an indirect statement, the subject of the infinitive goes into the accusative case.

Here, se is the subject of intellegere, not the direct object of dicit.

So the structure is:

• dicit = she says
• se = that she / herself
• unam litteram nondum intellegere = does not yet understand one letter

In other words, se is accusative because Latin indirect statement requires:

• accusative subject + infinitive

Because se is the reflexive pronoun, and it refers back to the subject of the main verb.

Here the subject of dicit is puella, so:

• dicit se ... intellegere = she says that she herself does not yet understand ...

If Latin used eam, that would normally mean her referring to some other female, not the girl who is speaking.

So:

• se = same person as the subject
• eam = some other female person

Because that is how Latin forms indirect statement.

After dicit, the reported idea is expressed with:

• an accusative subject (se)
• plus an infinitive (intellegere)

So English she says that she does not yet understand becomes Latin:

• dicit se ... nondum intellegere

The infinitive does not mean a simple dictionary to understand here; it is part of the whole reported statement.

Because the two words do not mean exactly the same thing here.

• litteras = a letter, an epistle
• litteram = a single letter of the alphabet

So the idea is:

• she rereads the letter from her mother
• and says she still does not understand one letter in it

This singular/plural contrast is very typical Latin usage.

Nondum means not yet.

That is stronger and more specific than simple non, which just means not.

So:

• non intellegit = she does not understand
• nondum intellegit = she does not understand yet

In this sentence, nondum suggests that she may understand it later, but at this moment she still does not.

Yes.

In the indirect statement:

• se is the subject of intellegere
• unam litteram is the direct object of intellegere

So the internal structure is:

• se = she
• unam litteram = one letter
• nondum intellegere = does not yet understand

Altogether: that she does not yet understand one letter

Very literal analysis would be:

• se = herself / that she
• unam litteram = one letter
• nondum = not yet
• intellegere = to understand

So, word for word, something like:

• she says herself one letter not yet to understand

But that is not natural English. Good English turns it into:

• she says that she does not yet understand one letter

This is a good example of why Latin should be understood by structure, not by forcing English word order onto it.