Mater filiae dicit se malle in bibliotheca sedere et commentarium legere quam in contione diu stare.

Here filiae is most naturally dative singular, meaning to the daughter.

That is a common pattern with dicere:

• aliquid alicui dicere = to say something to someone

So:

• Mater filiae dicit = The mother says to the daughter ...

A learner may notice that filiae could also, in isolation, be genitive singular (of the daughter). That is true as a bare form. But in this sentence, the syntax strongly favors the dative: dicit very naturally takes the person addressed in the dative.

Because Latin very often uses an indirect statement after verbs of saying, thinking, knowing, perceiving, and so on.

The standard pattern is:

• accusative subject + infinitive

So after dicit (she says), Latin gives:

• se malle = that she prefers

Literally, it is something like:

• she says herself to prefer

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

So the structure is:

• Mater ... dicit
• se malle ...

That whole infinitive phrase is what English would usually translate with that.

Se is the reflexive accusative pronoun. In an indirect statement, it refers back to the subject of the main clause.

So here:

• main subject = Mater
• indirect statement subject = se
• therefore se refers back to Mater

So the meaning is:

• The mother says that she herself prefers ...

If Latin wanted to say that the mother says the daughter prefers, it would use a non-reflexive form instead, such as eam or repeat the noun.

This is a very common point in Latin:

• se = refers back to the main subject
• eum / eam / eos / eas = refers to someone else

Yes. Malle is the infinitive of malo, which means to prefer.

Its principal parts are:

• malo, malle, malui

Historically, it comes from magis velle, literally to want more, but in standard Latin it functions as its own verb meaning prefer.

So:

• malo = I prefer
• malle = to prefer

In this sentence, malle is used because it is inside an indirect statement after dicit.

Because they depend on malle.

With malo / malle, Latin often uses infinitives to express the actions being preferred:

• malle sedere = to prefer to sit
• malle legere = to prefer to read
• malle stare = to prefer to stand

So in this sentence:

• se malle in bibliotheca sedere et commentarium legere
• quam in contione diu stare

means that the person prefers sitting and reading rather than standing.

In other words:

• malle is the main infinitive of the indirect statement
• sedere, legere, and stare are infinitives complementing malle

Here quam means than, and with malle it gives the idea rather than.

The pattern is:

• malle A quam B = to prefer A rather than B

So:

• in bibliotheca sedere et commentarium legere quam in contione diu stare

means:

• to sit in the library and read a commentary rather than stand for a long time in the assembly

Latin does not need to repeat malle in the second part. It is understood:

• se malle ... quam ...
• literally: she prefers ... than ...
• natural English: she prefers ... rather than ...

Because both are used with in to express location.

Rule:

• in + ablative = in / on / at a place
• in + accusative = into / onto a place, showing motion toward it

So:

• in bibliotheca = in the library
• in contione = in the assembly / at the public meeting

If there were motion into the library, Latin would use the accusative instead:

• in bibliothecam = into the library

Commentarium is accusative singular.

It is the direct object of legere:

• commentarium legere = to read a commentary / notebook / written account

That is why it is accusative: it is the thing being read.

A learner may also want to know the dictionary form:

• commentarius, commentarii (masculine) is very common
• but forms of this word can vary in meaning by context, and in some teaching materials you may see neuter-looking forms or adapted usage

In the sentence as given, the important syntactic point is simple:

• legere needs an object
• commentarium is that object

Diu is an adverb meaning for a long time or a long while.

It modifies stare:

• diu stare = to stand for a long time

Its position is flexible because Latin word order is much freer than English word order. Latin can place adverbs before or after the word they modify without changing the basic meaning.

So all of these would be understandable Latin in principle:

• diu stare
• stare diu

The chosen order may reflect style or emphasis, but the meaning stays the same.

Because Latin relies much more on inflectional endings than on fixed word order.

English usually needs a fairly strict order:

• subject + verb + object

Latin can move words around more freely because case endings and verb forms already show their grammatical roles.

In this sentence:

• Mater is nominative, so it is the subject
• filiae is dative, so it is the person addressed
• se is accusative, so it is the subject of the indirect statement
• commentarium is accusative, so it is the object of legere
• bibliotheca and contione are ablative after in, so they show location

That allows Latin to arrange words for emphasis or rhythm rather than following a rigid English-style order.

Not for this meaning.

After dicit, when Latin reports a statement such as she says that she prefers..., the normal construction is the accusative and infinitive:

• dicit se malle ...

A clause with ut is used for different purposes, especially:

• purpose
• result
• some kinds of substantive clauses after certain verbs

But after a simple verb of saying like dicit, Latin normally does not use ut to introduce ordinary reported speech.

So:

• dicit se malle ... = correct normal Latin for she says that she prefers ...

Grammatically, et directly joins:

• sedere
• legere

So the preferred actions are:

• to sit in the library
• and to read a commentary

Together those form the first side of the comparison, which is then contrasted with:

• quam in contione diu stare

So the structure is basically:

• to sit ... and read ...
• rather than to stand ...

In other words, et joins the two preferred actions, and the whole pair is set against the action introduced after quam.