Puella dicit se codicem suum in schola reliquisse.

Because after a verb like dicit (“says”), Latin very often uses an indirect statement construction rather than a clause with that.

So instead of saying something like “The girl says that she left her book,” Latin says:

• Puella dicit
• se reliquisse

Here se is the subject of the infinitive reliquisse. In indirect statement, the subject goes into the accusative case, so se means “herself / she” as the understood subject of reliquisse.

In other words:

• English: “The girl says that she left …”
• Latin: Puella dicit se … reliquisse

The se refers back to puella.

Because this sentence uses indirect statement (also called the accusative-and-infinitive construction).

After verbs of saying, thinking, knowing, hearing, and perceiving, Latin often uses:

• a main verb
• plus an accusative subject
• plus an infinitive

So:

• dicit = “she says”
• se reliquisse = “that she left”

The infinitive reliquisse is the perfect active infinitive of relinquere.

That perfect infinitive shows action earlier than the main verb:

• dicit = she says
• reliquisse = to have left / that she left

So the sense is: she is saying now that the leaving happened before.

Reliquisse is the perfect active infinitive of relinquere, meaning “to leave behind.”

Its principal parts are:

• relinquo
• relinquere
• reliqui
• relictum

The perfect infinitive is formed from the perfect stem:

• reliqu-
  • -isse = reliquisse

So reliquisse means:

• “to have left”
• or in smoother English inside indirect statement, simply “left”

Because it is the direct object of reliquisse.

The verb relinquere takes a direct object: you leave something somewhere.

Here, the thing left is codex (“book,” “notebook,” “manuscript volume,” depending on context). Its accusative singular is codicem.

So:

• nominative: codex
• accusative: codicem

That is why Latin has:

• se codicem suum … reliquisse
• “that she left her book …”

Because suus, sua, suum is the reflexive possessive adjective. It refers back to the subject of its own clause.

Here, in the indirect statement, the subject is se, and se refers back to puella. So suum means her own.

Thus:

• codicem suum = “her own book,” meaning the girl’s book

By contrast, eius would usually mean his/her/its referring to someone else, not back to the subject.

So:

• suum = her own book
• eius = someone else’s book

That distinction is very important in Latin.

It refers to puella.

A helpful way to see the structure is this:

• Main clause: Puella dicit
• Indirect statement: se codicem suum in schola reliquisse

Inside the indirect statement:

• se = the subject
• suum refers back to that subject

And since se refers back to puella, suum also ultimately refers to puella.

So the meaning is: the girl says that she herself left her own book at school.

Because in with the ablative often means in or at a place where something is located.

Here the idea is location:

• in schola = “in school” or “at school”

So schola is in the ablative singular.

Compare:

• in schola = in/at school (location)
• in scholam = into the school (motion toward)

Since the sentence describes where the book was left, not movement into the place, the ablative is used.

The basic pieces are:

• Puella = subject of the main verb
• dicit = main verb
• se = subject of the indirect statement
• codicem suum = object of reliquisse
• in schola = location
• reliquisse = infinitive completing the indirect statement

A more “unpacked” structure is:

• Puella dicit [se codicem suum in schola reliquisse].

Latin word order is fairly flexible because the endings show the grammar. But the given order is very natural:

1. main subject
2. main verb
3. indirect statement
4. infinitive often placed at or near the end

So yes, the order could vary, but this version is idiomatic and clear.

Because Latin normally does not use that in this kind of sentence.

In English we say:

• “The girl says that she left her book at school.”

In Latin, after verbs like say, think, know, and hear, the language typically prefers indirect statement:

• Puella dicit se codicem suum in schola reliquisse.

So the idea of English that is built into the accusative-plus-infinitive structure. There is no separate word needed here.

The main verb dicit is present tense: “she says.”

The infinitive reliquisse is perfect, which shows action completed before the time of the main verb.

So the sequence is:

• first: she left the book
• later: she says that she did so

That is why English often translates this as:

• “The girl says that she left her book at school”
• or more literally, “The girl says that she has left her book at school”

The key point is that the leaving happened earlier than the saying.

Usually no, at least not in the modern English sense.

In Latin, codex originally refers to a book, especially a bound set of pages or writing tablets; in many learning contexts it is glossed as book or notebook.

So in this sentence, codicem suum is best understood as something like:

• “her book”
• “her notebook”

not “her code.”

A good way is to identify the main finite verb first:

• dicit = “says”

Then ask: “What does she say?”

Everything that answers that question is the indirect statement:

• se codicem suum in schola reliquisse

Within that chunk:

• se = subject in accusative
• codicem suum = object
• in schola = place
• reliquisse = infinitive verb

So the whole embedded statement is:

• “that she left her book at school”

Here it is singular, because it refers to puella, which is singular.

However, se can be either singular or plural depending on context. Its form does not change between singular and plural, so you must determine the number from what it refers to.

In this sentence, since the antecedent is puella, it means:

• se = “herself” / “she”

not “themselves” / “they.”