لما دخلنا عالبناية، ما عرفنا وين قاعة الدرس لان الممر كان طويل وفيه ابواب كتير.

It is mostly Levantine colloquial Arabic. Some clear clues are وين for where, كتير for many/a lot, past negation with ما, and the contraction عالـ.

A more formal style would usually use forms like أين, كثيرة, and لم نعرف instead.

Here لما means when.

It is very common in spoken Levantine. A more formal equivalent would be عندما. Learners sometimes get confused because لما can have other uses in other kinds of Arabic, but in this sentence it is simply a time word meaning when.

Because Arabic often attaches the subject directly to the verb.

دخلنا = دخل + نا

• دخل = entered
• -نا = we

So the whole word means we entered. Arabic does not need a separate word for we here unless you want emphasis.

عالبناية is a spoken-style contraction of على البناية.

In Levantine, على + ال often becomes عالـ in pronunciation and writing. Even though على literally often means on, in colloquial Arabic it can be used more broadly with movement and destination. So here it works idiomatically as part of the idea of going into or entering the building, not literally being on the building.

In Levantine, ما is the normal way to negate a past-tense verb.

So:

• عرفنا = we knew / we found out
• ما عرفنا = we didn’t know / we couldn’t figure out

This is different from formal Arabic, where you would often see لم نعرف.

وين is the normal everyday Levantine word for where.

أين is formal and mostly used in Standard Arabic, writing, news, or very careful speech. In spoken Levantine, وين is what you would usually hear.

Because this is an idafa construction, also called a construct phrase.

قاعة الدرس literally has the structure hall of the lesson/class, and it naturally means the classroom or the lesson hall.

In an idafa:

• the first noun usually does not take ال
• the second noun can make the whole phrase definite

So قاعة الدرس is correct, while القاعة الدرس is not.

Arabic often leaves out the verb to be in this kind of structure.

So وين قاعة الدرس is literally something like where the classroom. In natural English, that becomes where the classroom was or where the classroom is, depending on context.

If a speaker wants to make the past more explicit, they could also say وين كانت قاعة الدرس.

لان means because.

In casual writing, people often drop the hamza, so لان is a relaxed spelling of لأن. In actual Levantine speech, many people also say لأنو or something similar in pronunciation, depending on the region.

So this is mainly a matter of informal spelling and spoken style.

Because الممر كان طويل is a very natural spoken Levantine word order.

Levantine often likes a topic + comment pattern:

• الممر = the corridor
• كان طويل = was long

Also, dialects do not use the case endings of Standard Arabic, so you get طويل rather than طويلًا.

Here فيه works like there is / there are.

So وفيه ابواب كتير means and there were many doors in natural English.

This is very common in spoken Arabic. Even though فيه literally comes from something like in it, it often functions as an existential expression. Some speakers might also say وكان فيه to make the past even clearer.

There are two things going on here.

First, ابواب is just a casual spelling of أبواب. Informal Arabic writing often leaves out the hamza.

Second, كتير in Levantine often behaves like a very common quantifier meaning many or a lot of, and it is often used without full agreement. So أبواب كتير is completely natural in speech.

You may also hear agreement forms like كتيرة in other contexts, but كتير after a plural noun is extremely common in Levantine.

A rough pronunciation would be:

lamma dakhálna ʿal-binaaye, ma ʿrifna ween qaaʿet id-dars, laan il-mamarr kaan ṭawiil w fiih abwaab ktiir

A few notes:

• الدرس is pronounced more like id-dars because د is a sun letter
• عالـ sounds like ʿal-
• vowels can vary by region, so different Levantine speakers may say it a little differently