الممثلة بهالمسلسل احسن من الممثل يلي شفته مبارح بالفيلم.

Because in Levantine Arabic, the verb to be is usually not expressed in the present tense.

So:

الممثلة بهالمسلسل احسن من...
literally looks like
the actress in-this-series better than...

But it naturally means:

The actress in this series is better than...

This is normal in Arabic. If you wanted the past or future, you would use a form of كان or another verb, but in the present, Arabic usually just puts the subject and the description together.

بهالمسلسل is a combination of several pieces:

• بـ = in / at / with depending on context
• هالـ = this
• مسلسل = series / TV series

So:

بهالمسلسل = in this series

A very useful pattern in Levantine is:

• هالبيت = this house
• هالبنت = this girl
• بهالمسلسل = in this series

You can think of هالـ as the common Levantine way to say this + noun.

Because this sentence is in Levantine colloquial Arabic, not Modern Standard Arabic.

In Levantine, instead of saying:

هذا المسلسل

people very often say:

هالمسلسل

Both mean this series, but هالمسلسل is the everyday spoken form.

So:

• MSA: هذا المسلسل
• Levantine: هالمسلسل

And with the preposition بـ, it becomes:

بهالمسلسل = in this series

احسن means better.

In Arabic comparative structures like:

X احسن من Y = X is better than Y

the comparative word usually stays in this basic form and does not change to match gender or number.

So even though الممثلة is feminine, you still say:

الممثلة احسن من...

not a special feminine form.

This is very normal. Comparatives like احسن, اكبر, اصغر, اجمل usually behave this way in this structure.

من here means than.

So:

• احسن = better
• احسن من = better than

This is the standard Arabic way to form comparisons:

• اكبر من = bigger than
• اصغر من = smaller than
• احسن من = better than

So the sentence is comparing the actress with the actor.

يلي is a very common Levantine relative word meaning:

• who
• that
• which

depending on the sentence.

So:

الممثل يلي شفته
= the actor that/who I saw

One very important point: in Levantine, يلي does not change for gender or number.

So the same word can be used for:

• the man who...
• the woman who...
• the people who...
• the thing that...

This is much simpler than Standard Arabic, which has forms like الذي, التي, الذين, etc.

Yes. In everyday Levantine, يلي and اللي are both very common spellings/forms of the same relative word.

So these are both natural:

• الممثل يلي شفته
• الممثل اللي شفته

Both mean:

the actor that/who I saw

Which one you hear more depends on region, speaker, and writing style.

شفته consists of:

• شفت = I saw
• ـه = him

So literally:

شفته = I saw him

In the sentence:

الممثل يلي شفته مبارح بالفيلم

this literally means something like:

the actor that I saw him yesterday in the movie

Even though that sounds odd in English, it is very normal in Levantine Arabic.

Because Arabic very often uses a resumptive pronoun inside relative clauses.

So in English you say:

the actor that I saw

But in Levantine Arabic, it is very natural to say:

the actor that I saw him

That ـه refers back to الممثل.

This is one of the things that often feels strange to English speakers at first, but it is extremely common and natural in spoken Arabic.

مبارح means yesterday.

Here it comes after شفته:

يلي شفته مبارح بالفيلم

This is very natural in Levantine. It tells you when the seeing happened.

Yes, adverbs like مبارح can sometimes move around depending on emphasis and style, but this placement is very common and easy:

• شفته مبارح
• مبارح شفته
• شفته بالفيلم مبارح

Some versions may sound more natural than others depending on context, but the sentence as given is completely normal.

بالفيلم = in the movie / in the film

It is built from:

• بـ = in
• الـ = the
• فيلم = movie / film

So:

بالفيلم = in the film

In this sentence, it belongs to the relative clause about the actor you saw. Depending on context, English might phrase this a little differently, but the Arabic is straightforward and natural.

Because the sentence is talking about specific people:

• الممثلة = the actress
• الممثل = the actor

Arabic uses الـ to mark definiteness, just like English uses the.

So this sentence is not about actresses and actors in general. It is about:

• a particular actress in this series
• a particular actor whom the speaker saw yesterday in the film

Yes, very much so.

Several features are strongly Levantine:

• هالمسلسل instead of هذا المسلسل
• احسن as a very natural everyday comparative
• يلي instead of Standard Arabic الذي / التي
• the overall spoken-style flow of the sentence

A more Standard Arabic version might look something like:

الممثلة في هذا المسلسل أفضل من الممثل الذي رأيته أمس في الفيلم.

That is grammatical Standard Arabic, but it sounds more formal and written.
Your original sentence sounds like everyday spoken Levantine.

Yes, roughly like this:

• الممثلة = the actress
• بهالمسلسل = in this series
• احسن = better
• من = than
• الممثل = the actor
• يلي = that / who
• شفته = I saw him
• مبارح = yesterday
• بالفيلم = in the movie

So the very literal order is:

The actress in this series better than the actor that I saw him yesterday in the movie.

That literal version is not good English, but it helps show how the Arabic sentence is put together.