Discipula volumen in scrinio relinquit, ut cras prooemium iterum legat.

Because discipula is in the nominative singular, which is the case normally used for the subject of a finite verb in Latin.

Here, discipula means the female student / schoolgirl and is the one doing the actions:

• relinquit = she leaves
• legat = she may read / might read

So discipula is the subject of both verbs, unless the context clearly suggests otherwise.

Volumen is in the accusative singular because it is the direct object of relinquit.

The verb relinquere means to leave behind, and the thing being left is the direct object:

• discipula volumen relinquit = the student leaves the scroll/book

A learner may expect a word like librum, but volumen often means a scroll or sometimes a book/work depending on context.

Because in can take either the ablative or the accusative, depending on the meaning.

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

Here the idea is that the book is being left in the desk/chest/case, so it describes where it is, not motion into it as the main focus:

• in scrinio = in the desk / in the writing case

So scrinio is ablative singular.

Scrinium is a neuter noun that can mean a box, case, cabinet, desk, or writing case, depending on context.

In a sentence like this, in scrinio usually suggests something like:

• in a desk
• in a writing case
• in a box/cabinet for storing texts

It is not necessarily a modern school desk; the exact picture depends on context.

Relinquit is third person singular present active indicative of relinquere.

It means:

• she leaves
• she is leaving
• sometimes, depending on context, a more vivid present

Latin often uses the simple present where English might also use a simple present. So this is just the normal main verb form for a straightforward statement.

Here ut introduces a purpose clause.

So:

• ut cras prooemium iterum legat = so that she may read the preface again tomorrow / in order to read the preface again tomorrow

This tells us why the student leaves the book in the desk.

A very common pattern in Latin is:

• main clause + ut + subjunctive for purpose.

Because after ut in a purpose clause, Latin normally uses the subjunctive.

So:

• legat = she may read / might read / should read
• not because the action is doubtful, but because Latin grammar requires the subjunctive in this kind of clause

If it were legit, that would be indicative, and it would not fit the normal grammar of a purpose clause.

So the pattern is:

• relinquit ... ut ... legat
• she leaves ... so that she may read ...

Legat is present subjunctive active, third person singular, from legere.

It is present subjunctive because the main verb relinquit is present, and Latin commonly uses the present subjunctive in a purpose clause after a primary tense main verb.

This is part of the sequence of tenses:

• primary tense in the main clause → often present subjunctive in the purpose clause

So:

• relinquit = present
• legat = present subjunctive

By default, it is the same subject as the subject of the main clause: the discipula.

Latin often does not repeat pronouns when the subject is clear from the verb ending and context. So the natural reading is:

• The student leaves the book in the desk so that she may read the preface again tomorrow.

If Latin wanted to make a different subject especially clear, it would usually signal that more explicitly.

Prooemium is accusative singular neuter and is the direct object of legat.

So:

• prooemium legat = she may read the preface/introduction

It is the thing being read.

They are adverbs.

• cras = tomorrow
• iterum = again

They modify legat:

• cras ... legat = read tomorrow
• iterum legat = read again

So the clause means that the student is leaving the book there for a future rereading:

• so that tomorrow she may read the preface again

Yes, but in a normal Latin way. Latin word order is more flexible than English word order because endings show the grammatical relationships.

The sentence is:

• Discipula volumen in scrinio relinquit, ut cras prooemium iterum legat.

A very literal unpacking would be:

• The student the scroll/book in the desk leaves, so that tomorrow the preface again she-may-read.

Latin often puts:

• the verb near the end of a clause
• important adverbs like cras and iterum where they are easy to notice
• the purpose clause after the main clause

So the word order is natural Latin, even though it does not match normal English order.

Not in this sentence.

Ut can have several meanings in Latin, including:

• as
• when
• so that / in order that

But here the combination of:

• a main action (relinquit)
• followed by ut
• followed by a subjunctive (legat)

strongly signals a purpose clause.

So here ut means so that / in order that, not when.

English often says:

• She leaves the book there to read the preface tomorrow.

Latin can sometimes express purpose in other ways, but one of its most common and standard ways is:

• ut + subjunctive

So instead of using a plain infinitive for purpose, Latin often prefers:

• ut ... legat = so that she may read

That is one of the key differences between English and Latin sentence structure.