Pater dicit se cotidianam vestem non gerere velle, quia dies sollemnis est.

Se is a reflexive pronoun, and here it refers back to pater, the subject of dicit.

Latin often uses se in indirect statement when the person being talked about is the same as the subject of the main verb:

• Pater dicit se velle... = The father says that he wants...

Here, he means the father himself, so Latin uses se, not eum.

A useful contrast:

• Pater dicit se velle... = the father says that he himself wants...
• Pater dicit eum velle... = the father says that that other man / him wants...

Because this is an indirect statement (also called accusative + infinitive).

After verbs like dicit (says), Latin often expresses that ... by using:

• a subject in the accusative
• a verb in the infinitive

So instead of saying something like pater dicit quod..., Latin commonly says:

• pater dicit se velle...

Literally, this is something like:

• the father says himself to want...

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

So:

• se = accusative subject of the infinitive velle

Because one infinitive depends on the other.

• velle = to want
• gerere = to wear

So:

• se ... velle = that he wants
• gerere velle = to want to wear
• non gerere velle = to want not to wear

The structure is:

• pater dicit = father says
• se ... velle = that he wants
• vestem non gerere = not to wear clothing

So the full thought is:

• Father says that he wants not to wear ordinary clothes

Because vestem is the direct object of gerere.

Gerere here means to wear, and the thing being worn is the direct object:

• vestem gerere = to wear clothing / a garment

So vestem is accusative because it receives the action of gerere.

Also, cotidianam agrees with vestem, so it is accusative feminine singular too:

• vestem = accusative feminine singular
• cotidianam = accusative feminine singular

It means everyday clothing, ordinary clothes, or daily dress.

The adjective cotidianus, -a, -um means daily, everyday, or ordinary depending on context.

So cotidianam vestem is not just any clothing, but specifically the kind of clothing one would normally wear on an ordinary day.

Since the sentence says quia dies sollemnis est, the contrast is clear:

• cotidianam vestem = ordinary/everyday clothes
• on a dies sollemnis = a special or ceremonial day

Because the negation is aimed most directly at gerere:

• non gerere velle = to want not to wear

This means the father does want something—namely, he wants not to wear ordinary clothes.

If the negation were aimed at velle, the sense would be different:

• non velle gerere = not to want to wear
• nolle gerere = to be unwilling to wear / not to want to wear

That is close in meaning, but not exactly the same emphasis.

So the sentence as written focuses on the action being avoided:

• he wants not to wear everyday clothing

Yes, Latin could have used nolle, since nolo means I do not want.

For example:

• Pater dicit se cotidianam vestem nol­le gerere

That would mean roughly:

• The father says that he does not want to wear everyday clothing

The version with non gerere velle is also perfectly understandable and emphasizes the negation with the lower infinitive:

• to want not to wear

So both are possible, but the sentence you have puts the not with wear, not with want.

Because Latin usually does not use a conjunction like English that after verbs of saying, thinking, knowing, and perceiving.

English says:

• The father says that he wants...

Latin usually says:

• Pater dicit se velle...

This is the normal indirect statement construction in Latin.

So English uses that + a finite verb, but Latin often uses:

• accusative subject + infinitive

Quia means because and introduces a reason clause.

So:

• quia dies sollemnis est = because it is a festival / ceremonial / special day

Unlike the indirect statement earlier in the sentence, this clause is a normal finite clause:

• dies = subject
• est = finite verb

So the sentence has two parts:

1. Pater dicit se cotidianam vestem non gerere velle
2. quia dies sollemnis est

That second part gives the reason.

Because dies is the subject of est, so it must be in the nominative.

• dies = nominative singular, subject
• sollemnis = nominative singular adjective agreeing with dies
• est = is

So:

• dies sollemnis est = the day is ceremonial / festive / special

English sometimes uses it is a special day, but Latin simply says the day is special.

Yes. Dies is usually masculine, especially when it means an ordinary day or a specific day in a general sense.

So:

• dies sollemnis = a solemn/festive day

You may learn that dies can sometimes be feminine in Latin, but in most basic examples like this, you should treat it as masculine.

Sollemnis means solemn, ceremonial, festive, or customary for a special occasion, depending on context.

In this sentence, the idea is that the day is not ordinary. It is a special occasion, which explains why the father does not want to wear ordinary clothes.

So dies sollemnis is something like:

• a festival day
• a ceremonial day
• a special day

Yes. You may see both cotidianus and quotidianus.

The form with qu- is very common in dictionaries and textbooks:

• quotidianus, -a, -um

But forms with co- also occur:

• cotidianus, -a, -um

So cotidianam vestem is not wrong. It is just a spelling variant you should recognize.

A helpful breakdown is:

• Pater = subject of the main verb
• dicit = main verb, says
• se = accusative subject of the indirect statement
• velle = infinitive in the indirect statement, to want
• cotidianam vestem = object phrase, everyday clothing
• non gerere = infinitive phrase depending on velle, not to wear
• quia dies sollemnis est = reason clause, because it is a special day

So the core structure is:

• Pater dicit
  • se ... velle
    • quia ... est

That is:

• The father says
  • that he wants ...
    • because ...

Very literally, you could map it like this:

• Pater = father
• dicit = says
• se = himself
• cotidianam vestem = everyday clothing
• non gerere = not to wear
• velle = to want
• quia dies sollemnis est = because the day is solemn/festive

So a very literal English version would be:

• Father says himself everyday clothing not to wear to want, because the day is festive.

That is bad English, of course, but it helps show how Latin is built.

A more natural English version is:

• The father says that he does not want to wear everyday clothes, because it is a special day.

or, more precisely matching the Latin structure:

• The father says that he wants not to wear everyday clothes, because it is a special day.