Estem a punt de pujar a la teulada perquè hi ha fulles seques a sobre.

Because estar a punt de + infinitive is a fixed expression meaning to be about to + verb.

So:

• Estem a punt de pujar = We are about to go up / climb
• not som a punt de...

In Catalan, ser and estar do not always match English to be in the same way. In this expression, you use estar.

A punt de means about to, just ready to, or on the verge of doing something.

Pattern:

• estar + a punt de + infinitive

Examples:

• Estic a punt de sortir. = I’m about to leave.
• Estan a punt de començar. = They’re about to begin.

So in your sentence:

• Estem a punt de pujar a la teulada = We’re about to go up onto the roof

Because the expression requires it:

• estar a punt de + infinitive

So you say:

• a punt de pujar
• a punt de marxar
• a punt de caure

You cannot normally remove the de here.

With pujar, Catalan often uses a to indicate the destination: to / onto a place.

So:

• pujar a la teulada = go up onto the roof
• pujar al cotxe = get into the car
• pujar a l’escenari = go up onto the stage

This is very natural Catalan. English may sometimes omit a preposition or choose a different one, but in Catalan a is normal here.

Teulada usually means the roof as the outer top covering of a building.

A useful distinction is:

• teulada = the roof, especially the outside/top part
• sostre = the ceiling, or sometimes roof in a more structural/general sense depending on context

So in this sentence, teulada is the natural word because the leaves are on top of the house, outside.

Here perquè means because, so it takes an accent.

Compare:

• perquè = because
• per què = why / for what reason
• per a què = what for / for what purpose

Examples:

• No surto perquè plou. = I’m not going out because it’s raining.
• Per què plou tant? = Why is it raining so much?

In your sentence, it gives the reason:

• perquè hi ha fulles seques a sobre = because there are dry leaves on top

Hi ha means there is or there are.

Examples:

• Hi ha un gos. = There is a dog.
• Hi ha dues cadires. = There are two chairs.

The hi is part of this very common structure. You should learn hi ha as a set expression.

In your sentence:

• hi ha fulles seques = there are dry leaves

Even though fulles is plural, Catalan still uses ha in hi ha:

• hi ha works for both singular and plural in modern standard usage.

Because in Catalan, adjectives often come after the noun.

So:

• fulles seques = dry leaves
• casa gran = big house
• cotxe nou = new car

Sometimes adjectives can come before the noun, but that usually changes the style, emphasis, or meaning. Here the normal, neutral order is:

• fulles seques

Also notice agreement:

• fulles is feminine plural
• so seques is also feminine plural

Because adjectives in Catalan usually agree with the noun in gender and number.

Here:

• fulla = leaf → feminine singular
• fulles = leaves → feminine plural

So the adjective must match:

• seca = dry (feminine singular)
• seques = dry (feminine plural)

That gives:

• fulles seques

Compare:

• un llibre sec = a dry book
• uns llibres secs = some dry books
• una fulla seca = a dry leaf
• unes fulles seques = some dry leaves

A sobre means on top, above, or up on top, depending on context.

In this sentence, it refers to leaves being on top of the roof area.

So:

• hi ha fulles seques a sobre = there are dry leaves on top

If you want to be extra explicit, Catalan can also say:

• a sobre de la teulada = on top of the roof

In your sentence, a sobre is understandable because the roof has just been mentioned.

They are related, but not always identical in feel.

• a sobre = on top / above
• damunt (de) = on top of / over
• sobre can be a preposition meaning on / over, but it is not always used in exactly the same way as English on

For example:

• El llibre és damunt la taula. = The book is on the table.
• El llibre és a sobre de la taula. = The book is on top of the table.

In your sentence, a sobre works well because it refers back to the roof in a natural way.

Yes. A fuller version would be:

• Estem a punt de pujar a la teulada perquè hi ha fulles seques a sobre de la teulada.

But this sounds repetitive, so Catalan often avoids repeating the noun when the reference is obvious.

That is why a sobre by itself sounds natural here.

It can suggest either, depending on context.

• pujar basically means to go up, to ascend, or sometimes to climb
• in this sentence, English could translate it as go up onto the roof or climb up onto the roof

If the action is physically difficult or involves scrambling, English climb may fit better. If it is just moving upward, go up is also fine.

So pujar is a flexible verb here.

The given sentence is natural, but Catalan allows some flexibility.

For example, you could also say:

• Com que hi ha fulles seques a sobre, estem a punt de pujar a la teulada. = Since there are dry leaves on top, we’re about to go up onto the roof.

Or:

• Estem a punt de pujar a la teulada, perquè hi ha fulles seques a sobre.

The original version is straightforward and very natural:

• statement first
• reason after perquè