Espero que te salga bien la entrevista mañana.

Because espero que normally triggers the subjunctive in Spanish when you are expressing a hope, wish, or expectation about something that is not yet a fact.

So:

• Espero que... = I hope that...
• after that, Spanish uses the subjunctive
• therefore: Espero que te salga bien...

This is very common:

• Espero que tengas suerte. = I hope you’re lucky.
• Espero que todo vaya bien. = I hope everything goes well.

Even though the event is in the future (mañana), Spanish still uses the present subjunctive here.

It comes from salir, which usually means to go out, to leave, or to come out.

Here, though, it is being used in a very common idiomatic way:

• salir bien = to go well / to turn out well
• salir mal = to go badly / to turn out badly

So te salga bien la entrevista means something like the interview goes well for you.

Salga is the yo-form stem of the present subjunctive of salir:

• yo salga
• tú salgas
• él/ella salga
• nosotros salgamos
• vosotros salgáis
• ellos salgan

It is irregular because salir has salg- in some forms.

Te means to you / for you.

With salir bien/mal, Spanish often expresses the person affected by the result:

• Me salió bien. = It went well for me.
• Te sale bien. = It goes well for you.
• Espero que te salga bien. = I hope it goes well for you.

So te is not the subject. The subject is really la entrevista.

You can think of the structure as:

• La entrevista te sale bien.
• literally: The interview comes out well to/for you
• naturally: The interview goes well for you

Because in this type of sentence, the thing that goes well is the interview.

So grammatically:

• la entrevista = subject
• te = indirect object / person affected
• salga = verb
• bien = adverb

If we changed the noun, the verb would change too:

• Espero que te salga bien el examen.
• Espero que te salgan bien los exámenes.

Notice how salga becomes salgan with the plural subject los exámenes.

Because Spanish and English do not always match word for word.

In English, we often say:

• I hope the interview goes well

In Spanish, one very natural way to express that is:

• Espero que te salga bien la entrevista

Here salir bien is an idiomatic expression. It does not mean the interview is physically going out. It means it turns out well or goes well.

Spanish also has other natural ways to say something similar, for example:

• Espero que te vaya bien en la entrevista.
• Espero que la entrevista te vaya bien.

These are also common, but salir bien is perfectly natural.

Spanish often uses the definite article where English might not.

In this sentence, la entrevista refers to a specific interview that both speakers know about: the interview tomorrow.

So Spanish naturally says:

• la entrevista

not usually:

• entrevista

This is very common in Spanish. Articles are used more often than in English.

Because after expressions like espero que, Spanish uses the present subjunctive to refer to a present or future situation.

So:

• Espero que te salga bien la entrevista mañana.

does not mean the interview is happening now. The word mañana makes the future time clear.

This is normal in Spanish:

• Espero que vengas mañana. = I hope you come tomorrow.
• Quiero que me llames luego. = I want you to call me later.

Spanish does not use the future tense after espero que in this kind of structure.

Yes. Spanish word order is flexible, although some versions sound more natural than others.

The original sentence is very natural:

• Espero que te salga bien la entrevista mañana.

You could also hear:

• Espero que mañana te salga bien la entrevista.
• Espero que la entrevista te salga bien mañana.

All of these are understandable. The position of mañana can shift depending on what the speaker wants to emphasize.

The original version sounds smooth and neutral.

Yes. That is also correct and natural.

Compare:

• Espero que te salga bien la entrevista.
• Espero que la entrevista vaya bien.
• Espero que te vaya bien en la entrevista.

They are all close in meaning, but the focus is slightly different:

• te salga bien la entrevista = I hope the interview goes well for you
• la entrevista vaya bien = I hope the interview goes well
• te vaya bien en la entrevista = I hope things go well for you in the interview

So the original sentence is a bit more personal because of te.

Yes. It sounds completely natural in Spain.

A speaker in Spain might very naturally say:

• Espero que te salga bien la entrevista mañana.

Other very natural Spain-Spanish alternatives would be:

• Que te salga bien la entrevista mañana.
• A ver si te sale bien la entrevista mañana.
• Espero que te vaya bien en la entrevista mañana.

The original sentence is polite, standard, and very idiomatic.

In standard Spanish, no. After espero, you normally need que before the subordinate clause.

So the correct version is:

• Espero que te salga bien la entrevista mañana.

Without que, it sounds non-standard or wrong in normal Spanish.

This is different from English, where that is often optional:

• I hope (that) it goes well

In Spanish, que is generally required here.