طلعنا السطح بالليل عشان الهوا كان احسن من جو الشقة.

Yes. Without vowels, طلعنا can be ambiguous in writing.

Here it means we went up / we went up to.

Why?

• In context, طلعنا السطح clearly means we went up to the roof.
• The ending -نا here is the we ending in the past tense.

A learner should know that the same spelling can also represent a causative meaning in other contexts, something like he took us up/out, but that would be understood from context and pronunciation.

In this sentence, read it as the simple verb:

• طلعنا = we went up

السطح means the roof or the rooftop.

In Egyptian Arabic, it often refers to the flat roof area of a building, which can function almost like a usable outdoor space. So طلعنا السطح often feels like we went up to the rooftop rather than just we went onto the roof in the English sense of standing on top of a house.

In Egyptian Arabic, verbs of motion often take the destination directly, especially in everyday speech.

So:

• طلعنا السطح = we went up to the roof

This is very natural colloquial Egyptian. English needs to, but Arabic does not always need an equivalent preposition here.

You may also hear prepositions in other expressions, but in this kind of sentence, leaving it out is normal.

بالليل means at night / during the night.

The بـ here is part of a very common time expression in Egyptian Arabic. It often appears with parts of the day or time phrases.

So:

• ليل = night
• بالليل = at night

It is best to learn بالليل as a fixed, common expression.

Here عشان means because.

So:

• طلعنا السطح بالليل عشان...
• We went up to the roof at night because...

In Egyptian Arabic, عشان is very common and can mean:

• because
• so that
• for

The exact meaning depends on context. In this sentence, it introduces the reason, so because is the best translation.

Here الهوا means the air or more naturally the breeze.

In a sentence like this, it usually suggests that the outdoor air felt nicer, cooler, or fresher.

So الهوا كان احسن is not just a scientific the air was better. It more naturally means something like:

• the air was nicer
• the breeze was better
• it felt better outside

Also, الهوا is the Egyptian spelling/pronunciation of what corresponds to MSA الهواء.

Literally, جو الشقة means the atmosphere of the apartment or the apartment’s air.

In natural English, this usually means:

• the air inside the apartment
• the atmosphere in the apartment
• possibly the stuffy air in the apartment

So the comparison is between:

• الهوا = the outdoor air/breeze
• جو الشقة = the indoor air/atmosphere of the apartment

This is a very natural way in Arabic to talk about how a place feels physically.

كان marks the idea as being in the past: was.

So:

• الهوا احسن = the air is better
• الهوا كان احسن = the air was better

Since the whole sentence is about what they did that night, the reason is also framed in the past:

• they went up to the roof
• because the air was better than the atmosphere in the apartment

احسن here means better, and it works as a comparative.

Comparatives like this do not behave like regular adjectives that need to match gender and number in the same way English learners may expect.

So:

• الهوا كان احسن = the air was better

Also, in informal writing, the hamza is often left out, so you may see:

• احسن instead of
• أحسن

Both represent the same word here.

من means than in comparisons.

So:

• احسن من = better than

Full phrase:

• احسن من جو الشقة = better than the atmosphere in the apartment

This is the normal way to form comparisons in Arabic:

• adjective/comparative + من

It is clearly Egyptian colloquial.

Some clues are:

• عشان instead of a more formal لأن
• الهوا instead of the more standard الهواء
• the overall casual structure and vocabulary choice

A more MSA-like version might look more formal and different in wording. But for everyday spoken Egyptian, this sentence sounds natural:

• طلعنا السطح بالليل عشان الهوا كان احسن من جو الشقة.