Ti riporto il libro domani.

Ti is the unstressed object pronoun for you in the singular, here meaning to you.

So in Ti riporto il libro domani, ti tells you who receives the book back: I’m bringing the book back to you tomorrow.

A native English speaker often expects something more like to you, but Italian usually uses a short pronoun before the conjugated verb:

• Ti porto il libro = I bring the book to you
• Ti scrivo = I write to you

Because riportare adds the idea of back or again.

• portare = to bring, carry
• riportare = to bring back, carry back

So:

• Porto il libro = I bring the book
• Riporto il libro = I bring the book back

In this sentence, the speaker is not just bringing a book somewhere; they are returning it.

Yes, riporto is one word.

It comes from:

• ri- = again, back
• portare = to bring/carry

So riportare literally has the sense of bring back.

This ri- prefix is very common in Italian:

• fare = to do → rifare = to do again
• leggere = to read → rileggere = to reread
• vedere = to see → rivedere = to see again

Italian often uses the present tense to talk about the near future, especially when there is a clear time expression like domani.

So:

• Ti riporto il libro domani literally uses the present tense
• but in natural English it is usually I’ll bring the book back to you tomorrow

This is very common in Italian:

• Parto domani = I’m leaving tomorrow / I’ll leave tomorrow
• Ci vediamo stasera = We’re seeing each other tonight / See you tonight

The word domani makes the future meaning clear.

The subject is I, even though io is not written.

Italian usually leaves subject pronouns out when the verb ending already shows who the subject is.
Riporto is the first person singular form, so it means I bring back.

Compare:

• riporto = I bring back
• riporti = you bring back
• riporta = he/she brings back

So the full version would be:

• Io ti riporto il libro domani

But io is normally unnecessary unless you want emphasis.

Because short object pronouns like mi, ti, ci, vi, lo, la, gli, le normally come before a conjugated verb in Italian.

So:

• Ti riporto il libro not
• Riporto ti il libro

This is standard clitic pronoun placement.

You will see pronouns attached to the end only in certain structures, such as:

• infinitives: riportarti
• imperatives: riportami
• gerunds: riportandoti

But with a normal conjugated verb like riporto, the pronoun goes before it.

Italian uses articles more often than English does.

In English, you might say I’ll bring back your book tomorrow or I’ll bring back the book tomorrow, depending on context. In Italian, a noun like libro usually needs an article unless there is some other determiner.

So il libro is perfectly normal here.

Other possibilities would change the meaning slightly:

• il libro = the book
• un libro = a book
• questo libro = this book
• il tuo libro = your book

Yes. Italian word order is flexible, and domani can move around without changing the basic meaning.

For example:

• Ti riporto il libro domani
• Domani ti riporto il libro
• Ti riporto domani il libro

The most natural choices are usually:

• Ti riporto il libro domani
• Domani ti riporto il libro

Moving domani can slightly change the emphasis:

• sentence-final domani often sounds neutral
• sentence-initial Domani emphasizes the time

Yes. Riportare has several meanings depending on context.

Common ones include:

• to bring back
• to report
• to quote
• to write down / record

But in Ti riporto il libro domani, the context clearly gives the meaning bring back, because the object is il libro and the pronoun ti shows the person receiving it.

So even though riportare can have other meanings, this sentence is understood as returning a book.

Yes. That is also correct, but it is slightly different in tone.

• Ti riporto il libro domani = I’ll bring the book back to you tomorrow
• Ti restituisco il libro domani = I’ll return the book to you tomorrow

Restituire focuses more on the idea of giving something back to its owner.
Riportare focuses more on bringing it back physically.

In many situations, both work, but riportare is especially natural when the physical act of bringing it back matters.

It is informal singular because of ti.

If you were speaking formally to one person, you would normally use Le instead:

• Le riporto il libro domani

So:

• ti = to you, informal singular
• Le = to you, formal singular

This is an important difference in Italian that English does not usually show.