La bisagra de la puerta hace ruido cuando la abro.

Yes. Both bisagra and puerta are feminine singular nouns, so they take la.

• la bisagra
• la puerta

That is also why the object pronoun later is la in la abro: it refers back to la puerta, which is feminine singular.

Bisagra means hinge, the metal part that lets a door open and close.

In this sentence, la bisagra de la puerta means the door hinge or more literally the hinge of the door.

Spanish very often expresses this kind of relationship with de:

• la bisagra de la puerta = the hinge of the door / the door hinge
• la manija de la puerta = the door handle
• el color de la casa = the color of the house

English often uses a noun before another noun (door hinge), but Spanish usually prefers noun + de + noun.

Hacer ruido is a very common Spanish expression meaning to make noise or to be noisy.

So:

• La bisagra hace ruido = The hinge makes noise
• very naturally, in context: The hinge squeaks / The hinge is noisy

Spanish often uses this broader expression instead of a more specific sound verb. You could sometimes use a more specific verb in other contexts, but hacer ruido is the normal, everyday phrasing.

Because this sentence describes something that happens regularly or generally:

• cuando la abro = when I open it / whenever I open it

This is a habitual statement, so the present tense is normal.

A useful contrast:

• cuando la abro = whenever I open it / when I open it (habitual)
• cuando la abra = when I open it (at some future time)

So here, abro is used because the speaker means this happens as a repeated fact.

Because la replaces la puerta, which was already mentioned.

• cuando abro la puerta = when I open the door
• cuando la abro = when I open it

Both are grammatically correct here. Using la avoids repeating la puerta and sounds more natural once the noun has already been introduced.

Because la puerta is the direct object of abrir.

You open something, so the thing opened is the direct object:

• abro la puerta
• la abro

That is why Spanish uses the direct object pronoun la.

Very simply:

• lo / la / los / las = direct object pronouns
• le / les = indirect object pronouns

In standard grammar, abrir takes a direct object here, so la is the expected form.

Because Spanish often leaves out subject pronouns when the verb ending already shows who is doing the action.

• abro = I open
• abres = you open
• abre = he/she opens

So cuando la abro already clearly means when I open it. Adding yo is possible, but usually unnecessary unless you want emphasis or contrast:

• cuando yo la abro = when I open it

Yes, that is grammatically correct. It just repeats la puerta.

Compare:

• cuando abro la puerta = when I open the door
• cuando la abro = when I open it

The version with la abro is more natural because Spanish, like English, often avoids repeating the same noun when the reference is obvious.

Each la is doing a different job:

1. La in La bisagra = the definite article with bisagra
2. la in de la puerta = the definite article with puerta
3. la in la abro = the direct object pronoun meaning it

So even though they look the same, they are not all the same kind of word.

Yes, Spanish word order is fairly flexible.

For example, these are all possible:

• La bisagra de la puerta hace ruido cuando la abro.
• Cuando la abro, la bisagra de la puerta hace ruido.
• La bisagra de la puerta hace ruido cuando abro la puerta.

The original version is very natural. Changing the order usually changes emphasis rather than basic meaning.

In most of Spain, hace is pronounced roughly AH-theh, because c before e or i is pronounced like the th in think.

So:

• hace → approximately AH-theh
• bisagra → roughly bee-SAH-gra
• puerta → roughly PWER-ta
• abro → roughly AH-bro

In Latin America, hace is usually pronounced with an s sound instead, but since you asked about Spain, the th sound is the one to expect in most peninsular accents.

Not always word-for-word. Depending on context, it can mean:

• when I open it
• whenever I open it

In this sentence, the idea is probably habitual: the hinge makes noise every time the speaker opens the door. So in natural English, whenever I open it may capture the sense especially well, even though Spanish still uses cuando.