Quiero construir una casa grande para mi familia.

Quiero is the first-person singular present tense of querer, so it means I want.

• yo quiero = I want
• It matches the subject I, even though Spanish often leaves out the pronoun yo because the verb ending already shows who is doing the action.

So Quiero construir... literally means I want to build...

After querer, Spanish normally uses a second verb in the infinitive.

So the pattern is:

querer + infinitive

Examples:

• Quiero comer = I want to eat
• Quiero dormir = I want to sleep
• Quiero construir = I want to build

This is very similar to English want to build, except Spanish does not need a separate word for to before the second verb.

Yes, construir means to build or to construct.

In this sentence, construir una casa means to build a house.

It is a regular -ir verb in many forms, though some forms have spelling/pronunciation changes, such as:

• construyo
• construyes
• construye

But in the sentence you gave, it appears in the infinitive, so you do not see those changes.

In Spanish, adjectives usually come after the noun, so:

• una casa grande = a big house

That is the normal and expected order.

If an adjective comes before the noun, it can sometimes sound more literary, emotional, or stylistically marked. For everyday Spanish, una casa grande is the standard way to say it.

Here, grande means big or large.

In una casa grande, it is simply describing the size of the house.

Sometimes adjective position can slightly affect nuance in Spanish, but in this sentence the natural reading is straightforward: a big house.

Also note:

• grande becomes gran before a singular noun in some cases:
  • una gran casa

But gran casa usually suggests great/impressive house more than just physically big house.
So una casa grande is the best choice if you mean size.

Para often means for, especially when showing:

• a recipient
• a purpose
• an intended destination or beneficiary

Here, para mi familia means the house is intended for my family.

So:

• Quiero construir una casa para mi familia = I want to build a house for my family

This is a very common use of para.

Mi without an accent is the possessive adjective meaning my.

• mi familia = my family

Mí with an accent is a prepositional pronoun meaning me, used after prepositions:

• para mí = for me
• sin mí = without me

So:

• para mi familia = for my family
• para mí = for me

That accent makes an important difference.

Spanish expresses this idea differently from English.

In English:

• I want to build

In Spanish:

• Quiero construir

After verbs like querer, Spanish goes straight to the infinitive, without adding a separate word equivalent to English to.

This also happens with many other verbs:

• Necesito estudiar = I need to study
• Prefiero salir = I prefer to go out

Una is the feminine singular form of the indefinite article, meaning a or one.

Because casa is a singular feminine noun, it takes una:

• una casa = a house

Compare:

• un libro = a book
• una casa = a house

You need una here because you are talking about a house, not just house in a general sense.

You know casa is feminine because it takes:

• una
• adjectives and other words that agree with feminine nouns when necessary

So:

• una casa
• la casa

Many nouns ending in -a are feminine, and casa is one of them.

Also, even though grande does not change form here for masculine/feminine singular, the article still shows the gender:

• una casa grande
• un piso grande

Spanish often omits subject pronouns because the verb ending already tells you who the subject is.

• quiero already means I want

So yo is not necessary:

• Quiero construir una casa grande...

You could say Yo quiero construir... if you want emphasis or contrast, for example:

• Yo quiero construir una casa, pero él quiere comprar una.

But in a neutral sentence, leaving out yo is completely normal.

Familia is singular here because it refers to my family as one unit.

Even though a family contains several people, Spanish treats familia as a singular noun in this context:

• mi familia
• una familia grande

You would use familias only if you were talking about more than one family:

• Quiero construir casas para varias familias.

In standard Peninsular Spanish, a rough pronunciation would be:

KYE-ro con-stroo-EER OO-na CA-sa GRAN-de PA-ra mi fa-MI-lya

A few useful notes for Spain:

• qu in quiero sounds like k
• r in quiero and para is a tapped r
• c before a in casa sounds like k
• j does not appear here, so there is no harsh throat sound in this sentence
• ll in familia is commonly pronounced like y in many varieties

A more Spanish-style approximation in IPA would be: /ˈkjeɾo kons.tɾuˈiɾ ˈuna ˈkasa ˈɡɾande ˈpaɾa mi faˈmilja/

Yes, you could, because edificar can also mean to build.

However:

• construir is broader and very common
• edificar can sound a bit more formal or technical depending on context

For a normal everyday sentence, construir una casa sounds very natural.

Yes, but the meaning changes slightly.

• una casa grande = a big house
• una gran casa = a great/impressive house

So if you are talking about physical size, casa grande is the better option.

If you want to praise the house as impressive, excellent, or important, gran casa can work.

The sentence follows this pattern:

[verb] + [infinitive] + [object] + [adjective] + [purpose/beneficiary phrase]

More specifically:

• Quiero = main verb
• construir = infinitive
• una casa = direct object
• grande = adjective describing casa
• para mi familia = prepositional phrase showing who it is for

So the structure is:

Quiero | construir | una casa grande | para mi familia.

This is a very useful pattern for making your own sentences:

• Quiero comprar un coche nuevo para mi hermano.
• Quiero preparar una cena especial para mis amigos.