Quan plou, el meu pare mira la teulada perquè hi ha una fuita a la cuina.

In Catalan, weather verbs usually do not need a subject pronoun. So plou by itself means it rains / it is raining.

• ploure = to rain
• plou = it rains / it is raining

So:

• Quan plou = When it rains

This is different from English, where you need the dummy subject it.

Catalan often uses the definite article before possessives, especially with family members and many everyday nouns.

So:

• el meu pare = my father
• literally, it looks like the my father, but that is normal in Catalan

This is one of the things English speakers have to get used to. The article is not translated into English here.

Pare is the normal Catalan word for father. In many contexts, it can also correspond to dad, depending on tone and context.

Some useful family words:

• pare = father / dad
• mare = mother / mum
• fill = son
• filla = daughter

So el meu pare is a completely natural everyday way to say my father.

It can suggest both, depending on context.

• mirar literally means to look at
• but in real usage, it can also mean to check, inspect, or have a look at

In this sentence, because there is a leak in the kitchen, mira la teulada likely means that the father is checking the roof to see where the problem is.

These two words are not the same:

• la teulada = the roof, especially the outside/top of the house
• el sostre = the ceiling, the inside upper surface of a room

Since the sentence talks about rain and a leak, la teulada is the logical choice: he is checking the outside roof, not the kitchen ceiling.

This is a very common question.

• perquè = because
• per què = why / for what

So in this sentence:

• perquè hi ha una fuita = because there is a leak

Compare:

• Per què plou? = Why is it raining?
• Plou perquè hi ha núvols. = It is raining because there are clouds.

The accent and spacing matter.

Hi ha means there is or there are.

Examples:

• Hi ha una fuita. = There is a leak.
• Hi ha dues cadires. = There are two chairs.

It comes from the verb haver. You do not need to analyze it too deeply at first; it is best learned as a fixed expression:

• hi ha = there is / there are

Unlike English, the same form works for both singular and plural.

Catalan often uses a where English uses in, at, or sometimes to.

So:

• a la cuina = in the kitchen
• literally, it looks like at the kitchen, but the natural English translation is in the kitchen

This is normal Catalan usage with places.

Yes, una fuita means a leak.

In this sentence, it means an unwanted escape of water, probably from the roof because of the rain.

Useful related words:

• una fuita d’aigua = a water leak
• una fuita de gas = a gas leak

So hi ha una fuita a la cuina means there is a leak in the kitchen.

The present tense in Catalan, as in English, can describe:

• something happening now
• something habitual or repeated
• a general situation

So this sentence can mean something like:

• When it rains, my father looks/checks the roof because there is a leak in the kitchen.

That sounds like a repeated situation, and the present tense is exactly the right tense for that.

Because Quan plou is an introductory subordinate clause.

The sentence structure is:

• Quan plou, = introductory time clause
• el meu pare mira la teulada = main clause
• perquè hi ha una fuita a la cuina = reason clause

The comma helps separate the opening clause from the main part of the sentence. This is similar to English:

• When it rains, my father checks the roof...

Yes, Catalan often drops subject pronouns like jo, tu, ell, etc., because the verb form usually shows the subject. But here pare is a noun, not a pronoun, and if you remove it, the meaning changes.

• El meu pare mira la teulada = My father looks/checks the roof
• Mira la teulada = He/She looks at the roof or Look at the roof!, depending on context

So the noun phrase el meu pare is needed here to make clear who is doing the action.

Both can refer to rain, but they are used a bit differently:

• plou = it rains / it is raining
• està plovent = it is raining right now, with more emphasis on the ongoing action

In a general or habitual sentence like this one, plou is the most natural choice:

• Quan plou... = When it rains...

If you said Quan està plovent, it would sound more specifically focused on the action being in progress, and it is less natural in this kind of general statement.