Allora, vieni in biblioteca con me oppure torni subito a casa?

Allora is very common in spoken Italian. Here it works like so, then, or well then in English.

In this sentence, it helps introduce a choice or move the conversation forward:

• Allora, vieni in biblioteca... = So, are you coming to the library...

It does not usually change the basic meaning much, but it makes the sentence sound natural and conversational.

Italian often leaves out subject pronouns because the verb ending already tells you who the subject is.

• vieni = you come / are you coming
• torni = you return / are you returning

Because both verb forms clearly show tu, Italian normally does not need to say tu unless it wants emphasis or contrast.

For example:

• Vieni con me? = Are you coming with me?
• Tu vieni con me? = Are you coming with me? (more emphasis)

Both vieni and torni are present tense, second person singular.

• vieni = from venire
• torni = from tornare

Italian often uses the present tense to talk about something happening right now or in the immediate future, just like English can do:

• Are you coming with me?
• Do you come with me? (less natural in English, but structurally similar)
• Are you going back home right away?

So in this sentence, the present tense is being used for a current decision or near-future action.

Italian distinguishes between movement toward the speaker and movement away from the speaker.

• venire = to come
• andare = to go

The speaker says vieni in biblioteca con me because the listener would be going with the speaker. From the speaker's point of view, that is coming with them, not simply going.

So:

• Vieni con me = Come with me
• Vai in biblioteca = Go to the library

Both can be possible in different contexts, but vieni con me is the natural choice here.

With places like biblioteca, Italian often uses in to mean to or into that place, especially when talking about being there or going there in a general sense.

• in biblioteca = to the library / in the library

Using alla biblioteca is possible in some contexts, especially if you are thinking of the building as a specific destination, but in biblioteca is extremely common and natural when talking about going there to study, read, work, etc.

Compare:

• Vado in biblioteca. = I’m going to the library.
• Sono in biblioteca. = I’m in the library.

After the preposition in, Italian often does not use an article with certain common places, especially when speaking in a general, functional way.

So:

• in biblioteca
• in banca
• in ufficio
• in chiesa

This is similar to how English sometimes says at school, at home, or in bed without focusing on a specific building as an object.

After a preposition such as con, Italian uses the stressed pronoun form, not the subject pronoun.

So:

• con me = with me
• con te = with you
• con lui = with him
• con lei = with her

You cannot say con io because io is a subject pronoun, not the form used after prepositions.

Both oppure and o can mean or.

• o is shorter and more neutral.
• oppure often sounds a little clearer, more deliberate, or slightly more emphatic.

In this sentence, oppure helps present a clear alternative:

• vieni in biblioteca con me oppure torni subito a casa?
• Do you come with me to the library, or do you go straight home?

Using o would also be correct:

• ...con me o torni subito a casa?

But oppure sounds a bit fuller and more natural in many spoken contexts.

Subito means immediately, right away, or straight away.

In Italian, adverbs like subito often come after the verb:

• torni subito = you go back right away

That is the most natural placement here. Italian word order is somewhat flexible, but torni subito is the standard choice.

Italian normally says a casa for home.

• torni a casa = you go back home
• sono a casa = I’m at home
• vado a casa = I’m going home

When Italian uses casa in the sense of home, it usually does not take the article.

Alla casa would usually refer to an actual house/building in a more literal sense, not the general idea of home.

It can mean both, depending on context.

• torni subito a casa = you go back home right away
• also literally you return home right away

In natural English, go back home is often the best translation here, even though the Italian verb is tornare.

In Italian, yes/no questions are very often made simply through intonation and punctuation, not by changing the word order like English does.

So:

• Vieni in biblioteca con me. = statement
• Vieni in biblioteca con me? = question

English usually needs an auxiliary verb:

• Are you coming with me to the library?

Italian does not need that. The same basic structure can work as either a statement or a question.

It is both: grammatically it is a question, but functionally it offers a choice.

The speaker is asking the listener to choose between two possibilities:

• vieni in biblioteca con me
• oppure torni subito a casa

So the tone is something like:

• So, are you coming to the library with me, or are you going straight home?

Yes. Italian present tense very often covers what English expresses with a present progressive or near future.

So all of these are close in meaning, depending on context:

• So, are you coming to the library with me, or are you going straight home?
• So, do you come to the library with me, or do you go straight home?
• So, will you come to the library with me, or will you go straight home?

The most natural English version is usually the first one, but the Italian present tense can carry that near-future meaning very easily.

A speaker would usually stress the two alternatives:

• Allora, vieni in biblioteca con me oppure torni subito a casa?

The voice often rises slightly at the end because it is a question. You may also hear extra stress on vieni and torni to highlight the choice:

• Do you come with me, or do you go home right away?

So the rhythm matters: the sentence is not just asking for information, but inviting a decision.