Quiero saber el origen de esa palabra.

Quiero is the first-person singular present form of querer: I want.

So:

• quiero = I want
• saber = to know

Together, quiero saber means I want to know.

This is a very common Spanish pattern: querer + infinitive.

Examples:

• Quiero comer = I want to eat
• Quiero ir = I want to go
• Quiero saber = I want to know

Spanish has two main verbs that can translate as to know:

• saber = to know a fact, piece of information, answer, skill, etc.
• conocer = to know a person, place, or to be familiar with something

In this sentence, the speaker wants information: the origin of that word. That is why saber is correct.

Compare:

• Sé la respuesta = I know the answer
• Conozco Madrid = I know Madrid / I am familiar with Madrid

So Quiero saber el origen... is about knowing information, not being acquainted with something.

Spanish often drops subject pronouns when they are clear from the verb form.

• quiero already tells us the subject is I
• so yo quiero and quiero both mean I want

In most cases, Spanish prefers the shorter version unless the speaker wants emphasis or contrast.

For example:

• Quiero saber el origen de esa palabra = normal
• Yo quiero saber el origen de esa palabra = more emphatic, perhaps contrasting with someone else

Because origen is a noun here, and Spanish usually uses an article with specific nouns more often than English does.

• el origen = the origin

In this sentence, the speaker is referring to a specific thing: the origin of that word.

So:

• Quiero saber el origen de esa palabra = natural
• Quiero saber origen de esa palabra = incorrect

Yes, origen is masculine: el origen.

Not all masculine nouns end in -o, and not all feminine nouns end in -a. Gender sometimes has to be learned with the noun.

Useful forms:

• el origen
• un origen
• los orígenes

Notice the plural changes slightly:

• origen → orígenes

Because origen normally goes with de in Spanish:

• el origen de algo = the origin of something

So:

• el origen de esa palabra = the origin of that word

This is just the normal preposition used with origen.

Similar examples:

• el nombre de la calle = the name of the street
• el color de la casa = the color of the house

Because in Spanish, a demonstrative like esa usually replaces the article instead of appearing with it.

So you say:

• esa palabra = that word

Not:

• la esa palabra

This is different from English structure, where that and the are separate words with different behavior. In Spanish, esa already does the job of pointing out the noun.

Other examples:

• este libro = this book
• esa casa = that house
• aquellos días = those days over there / those days back then

Esa means that, usually something not especially close to the speaker.

The three-way contrast is:

• esta = this
• esa = that
• aquella = that over there / that more distant one

So:

• esta palabra = this word
• esa palabra = that word
• aquella palabra = that word over there / that more distant word

In modern everyday Spanish, especially outside very careful distinction, the exact distance can be less strict than textbook explanations suggest. But esa palabra is the normal choice for that word.

Because palabra is a feminine noun: la palabra.

That is why the demonstrative is also feminine:

• esa palabra

If the noun were masculine, the demonstrative would change:

• ese libro = that book

So the agreement is:

• esa
  • feminine singular noun
• ese
  • masculine singular noun

Yes. A very common alternative is:

• Quiero saber de dónde viene esa palabra

Literally: I want to know where that word comes from

This often sounds very natural when talking about etymology or origin. The original sentence, Quiero saber el origen de esa palabra, is also completely correct and natural, but it is slightly more formal or abstract in tone because it uses the noun origen.

In standard Spain pronunciation, quiero is approximately:

• KYE-ro

More precisely, the qu before i sounds like a hard k, and the ie is a diphthong, so it sounds something like kye.

A rough guide:

• quiero → KYE-ro

Important points:

• the u in quie- is silent
• the stress is on the first syllable: QUIE-ro

In Spain, origen is approximately:

• o-RI-jen

The g before e sounds like the strong throaty sound also heard in j in Spanish from Spain.

So:

• origen → o-RI-khen or o-RI-hen, depending on how closely you want to imitate the Spanish sound

The stress is on the middle syllable:

• o-RI-gen

Because after quiero, Spanish normally uses an infinitive.

The structure is:

• querer + infinitive

So:

• quiero saber = I want to know
• quiero comer = I want to eat
• quiero estudiar = I want to study

Only the first verb is conjugated here:

• quiero = conjugated
• saber = infinitive

Yes. Quisiera saber el origen de esa palabra is correct and sounds more polite, softer, or more formal.

Compare:

• Quiero saber... = I want to know...
• Quisiera saber... = I would like to know...

Both are good, but quisiera can sound more courteous in conversation, especially when asking someone for information.