Quiero vino tinto.

Spanish often drops subject pronouns when they are not needed. The verb form quiero already tells you the subject is I, because it is the first person singular form of querer.

So:

• Quiero vino tinto = I want red wine
• Yo quiero vino tinto = also correct, but yo is usually added only for emphasis, contrast, or clarity

In neutral everyday Spanish, leaving out yo sounds very natural.

Quiero comes from the verb querer, which usually means to want.

Here it is in the present tense, first person singular:

• yo quiero = I want

A useful mini-pattern:

• quiero = I want
• quieres = you want
• quiere = he/she/you (formal) wants
• queremos = we want
• queréis = you all want (Spain)
• quieren = they/you all want

Notice that querer is not fully regular:

• querer
• quiero

The e changes to ie in several forms.

Because vino can be used as an uncountable noun when you mean wine in a general sense.

So:

• Quiero vino tinto = I want red wine / I want some red wine
• Quiero un vino tinto = I want a red wine / a glass of red wine / one red wine

In real life, if you are ordering in a bar or restaurant, Quiero un vino tinto is often more natural because it sounds like you are asking for one serving. Without un, the sentence sounds more general.

Yes, absolutely.

There is a small difference in feel:

• Quiero vino tinto
  More general: I want red wine
• Quiero un vino tinto
  More specific in a café/bar/restaurant: I want a red wine / a glass of red wine

In everyday ordering situations in Spain, people often say things like:

• Un vino tinto, por favor
• Quiero un vino tinto
• Me pone un vino tinto, por favor (very natural in Spain)

So the version with un is extremely common.

In Spanish, adjectives usually come after the noun.

So:

• vino tinto = red wine
• literally: wine red

This is one of the big differences from English, where adjectives usually come before the noun.

Other examples:

• coche rojo = red car
• casa grande = big house
• vino blanco = white wine

So vino tinto follows the normal Spanish pattern: noun + adjective.

Because vino tinto is the normal expression for red wine in Spanish.

Even though rojo means red, wine is usually described as:

• vino tinto = red wine
• vino blanco = white wine
• vino rosado = rosé wine

So for wine, tinto is the standard word. Saying vino rojo would sound unusual or unnatural in most contexts.

It is grammatically correct, and people will understand you perfectly, but on its own it can sound a bit direct.

In Spain, depending on the situation, people often soften requests with phrases like:

• Quisiera vino tinto = I would like red wine
• Me gustaría vino tinto = I would like red wine
• Un vino tinto, por favor = A red wine, please
• Me pone un vino tinto, por favor = Could you get me a red wine, please?

So Quiero vino tinto is not wrong, but if you are ordering politely, something with por favor, or a softer structure, may sound more natural.

A simple pronunciation guide is:

• Quiero ≈ KYEH-ro
• vino ≈ BEE-no
• tinto ≈ TEEN-to

A few details:

• In quiero, the quie sounds like kye.
• In Spanish, v and b are pronounced very similarly, so vino may sound a bit like bino to English speakers.
• The r in quiero is a light tap, not a strong English r.
• The stress is:
  • QUIE-ro
  • VI-no
  • TIN-to

Normally, Quiero vino tinto is the standard order:

• verb + noun + adjective

You generally would not say:

• Quiero tinto vino ✘

That sounds wrong.

You can move things around in special contexts for emphasis, but for a learner, the normal order is the one to use:

• Quiero vino tinto

If you want a very natural ordering phrase in Spain, you could also say:

• Un vino tinto, por favor

It can be understood either way, depending on context.

• In a general conversation, Quiero vino tinto may sound like a preference or desire: I want red wine
• In a bar or restaurant, it can function as an order, but it may sound a little abrupt or incomplete compared with more natural ordering phrases

In Spain, if you are ordering, these often sound more natural:

• Un vino tinto, por favor
• Quiero un vino tinto
• Me pone un vino tinto, por favor

So the sentence is correct, but context matters a lot.