Mater dicit pallam non minus utilem esse quam ornamentum pretiosum.

A useful way to divide it is:

• Mater dicit = the main clause, Mother says
• pallam non minus utilem esse quam ornamentum pretiosum = what she says

Inside that second part:

• pallam = the thing being talked about
• utilem esse = to be useful
• non minus ... quam = not less ... than
• ornamentum pretiosum = the thing it is being compared with

So the sentence uses a very common Latin pattern: a main verb of saying, followed by an indirect statement.

Because after dicit Latin normally uses an accusative + infinitive construction for indirect statement.

In English, we say:

• Mother says that the cloak is useful

In Latin, instead of using that plus a normal finite verb, Latin usually says:

• Mother says the cloak to be useful

That sounds strange in English, but it is normal Latin. In this pattern:

• the subject of the indirect statement goes into the accusative
• the verb goes into the infinitive

So:

• direct statement: Palla utilis est
• indirect statement after dicit: pallam utilem esse

That is why you see pallam, not palla.

Esse is the infinitive of sum, meaning to be.

Because dicit introduces an indirect statement, the verb inside that statement appears as an infinitive. The underlying idea is:

• direct: Palla utilis est = The cloak is useful
• indirect: Mater dicit pallam utilem esse = Mother says that the cloak is useful

So esse is simply the infinitive form required by the indirect statement construction.

Because utilem agrees with pallam.

Since pallam is:

• feminine
• singular
• accusative

the adjective describing it must also be:

• feminine
• singular
• accusative

So:

• nominative feminine singular: utilis
• accusative feminine singular: utilem

That is why the sentence has pallam ... utilem esse.

Latin usually does not use a separate word meaning that after verbs like say, think, know, hear, and so on.

Instead, it uses the accusative + infinitive construction.

So English:

• Mother says that the cloak is useful

becomes Latin:

• Mater dicit pallam utilem esse

So the idea of that is there, but it is expressed by the whole construction, not by a single word.

Non minus ... quam means not less ... than.

Here it means that the cloak is at least as useful as the expensive ornament.

So these are equivalent in sense:

• not less useful than
• no less useful than
• at least as useful as

This is a very common Latin comparison pattern.

Because after quam, Latin is comparing the first idea with an understood second clause.

The sense is roughly:

• Mother says that the cloak is no less useful than an expensive ornament is useful

In that understood comparison, ornamentum pretiosum is the subject of the implied clause, so it appears in the nominative.

You can think of the full underlying comparison as something like:

• pallam non minus utilem esse quam ornamentum pretiosum utile est

Latin normally leaves out the repeated utile est, because it is obvious.

So ornamentum pretiosum is nominative because it belongs to that understood clause after quam, not because it is the subject of dicit.

Because pretiosum is an adjective modifying ornamentum, and adjectives in Latin agree with the nouns they describe in:

• gender
• number
• case

Here ornamentum is:

• neuter
• singular
• nominative

So pretiosum must also be:

• neuter
• singular
• nominative

That is why both words end in -um.

The word order is natural, but Latin word order is fairly flexible.

This sentence puts the words in a clear and elegant order:

• Mater dicit first gives the speaker and the act of speaking
• pallam introduces the subject of the indirect statement
• non minus utilem esse gives the main claim
• quam ornamentum pretiosum finishes with the comparison

Latin could rearrange parts of this sentence and still keep the same basic meaning, because the endings show the grammar. But the given order is a very normal one.

A palla is a kind of cloak, mantle, or shawl, traditionally associated with women in Roman dress.

So it is not just any random cloth. It refers to a recognizable garment. In a sentence like this, it suggests something practical and wearable, which fits the comparison with a decorative luxury item.

It would be:

• Palla non minus utilis est quam ornamentum pretiosum

That is the ordinary direct statement:

• The cloak is no less useful than an expensive ornament

When that direct statement is turned into indirect statement after dicit:

• palla becomes pallam
• utilis becomes utilem
• est becomes esse

So:

• direct: Palla non minus utilis est quam ornamentum pretiosum
• indirect: Mater dicit pallam non minus utilem esse quam ornamentum pretiosum