Quiero una hamburguesa.

In Spanish, the subject pronoun is often left out because the verb ending already shows who is doing the action.

• quiero = I want
• The -o ending tells you it is first person singular: I

So Quiero una hamburguesa is perfectly natural. You could say Yo quiero una hamburguesa, but that usually adds emphasis, contrast, or clarity.

For example:

• Quiero una hamburguesa. = neutral, normal
• Yo quiero una hamburguesa. = I want a hamburger

Quiero is the first-person singular present tense of querer.

So:

• querer = to want
• quiero = I want

This verb is irregular in the present tense:

• yo quiero
• tú quieres
• él/ella/usted quiere
• nosotros queremos
• vosotros queréis
• ellos/ellas/ustedes quieren

A common thing to notice is the stem change:

• e → ie in most forms
• but not in nosotros and vosotros

Because hamburguesa is a feminine noun in Spanish.

Spanish indefinite articles must match the gender of the noun:

• un for masculine singular nouns
• una for feminine singular nouns

So:

• un bocadillo
• una hamburguesa

Even though a hamburger does not have biological gender, Spanish nouns still have grammatical gender.

Usually, yes: nouns ending in -a are often feminine, and hamburguesa is one of them.

So:

• la hamburguesa
• una hamburguesa

But this is only a general pattern, not a perfect rule. Some nouns ending in -a are masculine, such as:

• el día
• el mapa

Still, for hamburguesa, feminine is correct.

In most normal situations, you would say Quiero una hamburguesa.

Spanish usually prefers an article here when you mean one hamburger. Saying Quiero hamburguesa sounds incomplete or unnatural in most everyday contexts.

Compare:

• Quiero una hamburguesa. = I want a hamburger.
• Quiero hamburguesas. = I want hamburgers.
• Quiero comer hamburguesa. = I want to eat hamburger / hamburger meat.
  This is more generic and less likely in a restaurant-ordering situation.

So if you are ordering or asking for one item, una is the natural choice.

A simple approximate pronunciation for an English speaker is:

KYEH-ro OO-na am-boor-GHEH-sa

A few key points:

• quiero: the qu sounds like k
• ie is pronounced like a quick ye
• r in quiero is a light Spanish r, not a strong English r
• una = OO-na
• h in hamburguesa is silent
• gu before e gives a hard g sound, like g in get

So hamburguesa sounds roughly like: am-boor-GHEH-sa

In standard Spanish, h is silent.

So:

• hamburguesa is pronounced as if the word began with a
• not with an English h sound

This is true for many Spanish words:

• hola
• hotel
• hacer

The letter is still written, but normally not heard.

This follows a very common Spanish word order:

verb + object

• Quiero = I want
• una hamburguesa = a hamburger

So literally:

• I want a hamburger

This is the same basic order as in English, so it is straightforward here.

It is understandable and common, but it can sound a little direct depending on the situation.

In casual contexts, it is often fine. But in a restaurant or shop, Spanish speakers often use something softer, such as:

• Quería una hamburguesa.
• Me gustaría una hamburguesa.
• Para mí, una hamburguesa.

These sound more polite or more natural when ordering.

So:

• Quiero una hamburguesa = correct, direct
• Me gustaría una hamburguesa = more polite

Both are correct, but they have a different tone.

• Quiero una hamburguesa = I want a hamburger

  • direct
  • clear
  • sometimes a bit blunt in service situations

• Me gustaría una hamburguesa = I would like a hamburger

  • softer
  • more polite
  • very common when ordering

If you are just practicing the verb querer, Quiero una hamburguesa is a great example. If you are actually ordering in a restaurant, Me gustaría una hamburguesa may sound more natural.

Yes, depending on context, hamburguesa can refer to:

• the whole hamburger / burger
• the hamburger patty
• hamburger meat in some contexts

Usually, in a sentence like Quiero una hamburguesa, people will understand it as I want a hamburger.

Context tells you which meaning is intended. In a restaurant, it will almost always mean the full burger.