Mater miratur cur puer stilum suum semper amittat.

Because miror, mirari, miratus sum is a deponent verb. Deponent verbs use passive-looking forms but have active meanings.

So:

• miratur looks like he/she/it is wondered at
• but actually means he/she/it wonders or is amazed

Here, mater miratur = the mother wonders.

Mater is nominative singular. In Latin, the subject of a finite verb is normally in the nominative case.

Since miratur is 3rd person singular, mater fits as its subject:

• mater = mother
• miratur = she wonders

So mater is the subject of the main clause.

Cur means why. It introduces a question about reason.

In this sentence, the mother is wondering why the boy keeps losing his stylus, so cur is exactly the right word to introduce that idea.

Latin often uses:

• cur = why
• quid = what
• ubi = where
• quis / quid = who? / what?

Here the subordinate clause is an indirect question, and cur introduces it.

Because cur puer stilum suum semper amittat is an indirect question after miratur.

In Latin, indirect questions normally take the subjunctive. So:

• direct question: Cur puer stilum suum semper amittit?
• indirect question: Mater miratur cur puer stilum suum semper amittat.

That is one of the most important things to notice in the sentence.

Amittat is present subjunctive, 3rd person singular of amittere.

It is used here because:

1. the subject is puer = the boy → so the verb must be 3rd singular
2. the main verb miratur is present
3. the indirect question refers to something happening at the same time as the wondering

So the present subjunctive is the natural form here.

Because puer is the subject of amittat.

Even inside a subordinate clause, the subject is still in the nominative. So in the indirect question:

• puer = subject
• amittat = verb
• stilum suum = direct object

The fact that it follows cur does not change its case.

Stilum is accusative singular. It is the direct object of amittat.

The verb amittere means to lose, and what is being lost is the stylus. So Latin puts stilus into the accusative:

• nominative: stilus
• accusative: stilum

That is why the sentence has stilum suum.

Suum is the reflexive possessive adjective. It refers back to the subject of its own clause.

In the clause cur puer stilum suum semper amittat, the subject is puer, so:

• suum = his own

That means the boy is losing his own stylus.

If Latin used eius, that would normally mean his in a non-reflexive sense, referring to someone else’s stylus, not the boy’s own.

Suum agrees with stilum, not with puer.

Adjectives in Latin agree with the noun they describe in:

• gender
• number
• case

So:

• stilum = masculine, singular, accusative
• suum = masculine, singular, accusative

But in meaning, suum refers back to the subject of the clause, which is puer.

Semper means always, and it modifies the verb amittat.

So the sense is:

• why the boy always loses his stylus

In Latin, adverbs like semper can move around fairly freely, so its position does not have to match English exactly.

Not really. Latin word order is much more flexible than English word order.

This sentence is arranged quite naturally:

• Mater miratur = main clause first
• cur puer stilum suum semper amittat = indirect question after it

Within the subordinate clause:

• puer = subject
• stilum suum = object
• semper = adverb
• amittat = verb at the end

Putting the verb at the end is very common in Latin.

A stilus was a Roman writing tool, usually used for writing on wax tablets. One end was pointed for scratching letters, and the other could be used to smooth the wax.

So stilum is often translated as:

• stylus
• sometimes more loosely pen

But stylus is the more exact historical meaning.

It can mean either in different contexts, because miror has a range of meanings such as:

• wonder
• marvel
• be amazed at

Here, because it is followed by cur plus an indirect question, wonders is the best fit:

• The mother wonders why...

Without the indirect question, it might more naturally mean is amazed at something.

There are two:

1. Mater miratur — the main clause
2. cur puer stilum suum semper amittat — a subordinate clause, specifically an indirect question

So the whole sentence is built from a main statement plus the content of what the mother is wondering.

No, not here.

An infinitive construction is common in Latin for indirect statements, but not for indirect questions.

For example:

• indirect statement: Mater putat puerum stilum amittere.
• indirect question: Mater miratur cur puer stilum amittat.

Because the idea is why does he lose it?, Latin needs an interrogative word like cur and a subjunctive verb, not an infinitive.