كنت عم شوف الشاشة لما اشتغلت الكاميرا لحالها.

It is a very common Levantine way to express the past continuous:

• كنت = I was
• عم = a marker showing an ongoing action
• شوف = see / watch

So كنت عم شوف means I was watching or I was looking at.

This pattern is extremely useful in Levantine:

• كنت عم باكل = I was eating
• كنت عم بكتب = I was writing
• كنت عم شوف = I was watching

In this sentence, it shows that the action of watching the screen was already in progress.

In many Levantine varieties, the verb after عم may appear in a shorter colloquial form, so شوف here stands for أشوف.

So:

• عم شوف
• عم أشوف

Both can be heard, depending on region and speaking style.

A learner should mainly understand that in this sentence, عم شوف means I am / was watching in dialect speech. The dropped أ is normal in casual Levantine.

Arabic usually does not need an explicit subject pronoun if the verb already shows who is doing the action.

Here:

• كنت already tells you the subject is I
• شوف in this structure also matches that first-person meaning from context

So Arabic can say the equivalent of was watching without separately saying I.

You could add أنا for emphasis:

• أنا كنت عم شوف الشاشة...

But normally it is unnecessary.

الشاشة means the screen.

The ال at the beginning is the Arabic definite article, meaning the.

So:

• شاشة = a screen
• الشاشة = the screen

Because the sentence refers to a specific screen, Levantine uses الشاشة.

Also, the ش in الشاشة is pronounced like sh in shop.

Here لما means when.

It introduces the event that happened during the ongoing action:

• كنت عم شوف الشاشة = I was watching the screen
• لما اشتغلت الكاميرا = when the camera turned on

So the structure is:

• ongoing background action
• then a specific event happens

This is very common with لما in stories and everyday speech.

Because Arabic often uses the perfect/past form for the shorter event that happened at that moment.

In this sentence:

• كنت عم شوف = ongoing background action
• اشتغلت = the event that happened suddenly within that background

So the aspect contrast is:

• past continuous for the longer action
• simple past/perfect for the interrupting event

This is very natural in Arabic, just like in English:

• I was watching the screen when the camera turned on.

Because الكاميرا is treated as feminine, so the verb agrees with it.

• اشتغل = he/it turned on
• اشتغلت = she/it turned on

Since الكاميرا is feminine in Arabic, Levantine says:

• اشتغلت الكاميرا

This is normal even for borrowed words like camera.

Yes, اشتغل often means to work, but in Levantine it can also mean:

• to start working
• to switch on
• to become active / start operating

So with devices, اشتغلت الكاميرا means something like:

• the camera turned on
• the camera started working

That is a very common usage for electronics and machines.

لحالها means by itself, on its own, or automatically depending on context.

It is made of:

• لـ / لحال = by oneself / alone / on one’s own
• ها = her/it, referring to the camera

So:

• لحالي = by myself
• لحالك = by yourself
• لحالها = by herself / by itself
• لحالهم = by themselves

In this sentence, لحالها tells you the camera switched on without someone doing it.

Because Arabic uses gender for nouns, and الكاميرا is feminine.

So the pronoun attached to لحال has to match the noun:

• masculine thing: لحالو
• feminine thing: لحالها

Since camera is feminine:

• اشتغلت الكاميرا لحالها

That literally means something like the camera turned on by itself.

Sometimes you may hear similar forms, but كنت عم شوف is the clearest way to show an action was in progress in the past.

Compare:

• كنت عم شوف الشاشة = I was watching the screen
• كنت بشوف الشاشة = in some contexts, this can sound more habitual or dialect-dependent

For a learner, the safest takeaway is:

• عم strongly marks the ongoing action
• كنت عم + verb is a very common Levantine past continuous pattern

It is specifically Levantine Arabic, not Modern Standard Arabic.

The clearest dialect features are:

• عم for ongoing action
• شوف in this colloquial form
• لحالها in a natural spoken-dialect sense

A more MSA-style sentence would look quite different, for example using a structure like كنت أشاهد الشاشة عندما...

So if you learn this sentence as written, think of it as everyday spoken Levantine.

It breaks down like this:

• كنت عم شوف الشاشة = I was watching the screen
• لما = when
• اشتغلت الكاميرا = the camera turned on
• لحالها = by itself

So the sentence follows a very common narrative pattern:

1. background action in progress
2. sudden event
3. extra detail about how it happened

That makes it a great model for building similar sentences, such as:

• كنت عم ادرس لما رن التلفون.
  I was studying when the phone rang.

• كنت عم اسوق لما طفيت السيارة لحالها.
  I was driving when the car shut off by itself.