الفترة التجريبية بتبلش بكرا.

A natural Levantine pronunciation is:

il-fatra t-tajrībiyye btballesh bokra

A few notes:

• الفترة → il-fatra / el-fatra
• التجريبية → it-tajrībiyye
  The ت is a sun letter, so the ل of ال assimilates. You hear t-t..., not al-t...
• بتبلش → btballesh / btiballish, depending on region
• بكرا → bokra / bukra

So the whole sentence sounds clearly colloquial, not fully MSA.

It is a noun + adjective phrase:

• فترة = period
• تجريبية = trial / experimental / probationary

Together, الفترة التجريبية means the trial period or the probationary period, depending on context.

Also, تجريبية comes from the idea of trying/testing something, from the root ج ر ب.

No, this is not an idaafa.

It is a regular noun + adjective phrase:

• الفترة = the period
• التجريبية = the trial/probationary

In Arabic, adjectives usually:

• come after the noun
• match the noun in definiteness

So:

• الفترة التجريبية = the trial period
• فترة تجريبية = a trial period

If it were an idaafa, the structure would work differently.

Yes, it is the colloquial Levantine equivalent of to start / to begin.

The verb here is from بلّش / يبلّش, which is very common in Levantine Arabic.

So:

• Levantine: بتبلش
• MSA equivalent: تبدأ

A native speaker would often say بلّش in everyday speech instead of the more formal بدأ.

They each do something important:

• تـ marks the imperfect form here, and can mean she/it or you (masculine singular) depending on context
• بـ is the common Levantine present/imperfect marker

So بتبلش can mean:

• she starts
• it starts
• you start (masculine singular)

In this sentence, because the subject is explicitly الفترة and that noun is feminine, the meaning is clearly it starts.

Because فترة is a feminine noun.

In Arabic, verbs agree with singular subjects in gender, so a feminine singular subject takes a feminine singular verb form.

That is why you get:

الفترة التجريبية بتبلش بكرا

Literally, it is something like:

the period — it starts tomorrow

If the subject were masculine, you would usually get a masculine form, for example:

الدوام بيبلش بكرا = work starts tomorrow

Because Levantine often uses the present/imperfect for the future when there is already a future time word like بكرا.

So بتبلش بكرا naturally means starts tomorrow.

This is similar to English:

• The course starts tomorrow
• The trial period starts tomorrow

If you want to mark the future more explicitly, you can say:

الفترة التجريبية رح تبلش بكرا
or
الفترة التجريبية حتبلش بكرا

Usually, after رح or حـ, you use تبلش, not بتبلش.

Yes.

On its own, بتبلش is ambiguous. It can mean:

• you start (masculine singular)
• she starts
• it starts for a feminine noun

But in this sentence, the subject الفترة التجريبية is stated clearly, so there is no confusion: it means the trial period starts.

This kind of overlap is very common in Arabic imperfect verb forms.

Yes. The sentence can be rearranged depending on what you want to emphasize.

Some natural possibilities are:

• الفترة التجريبية بتبلش بكرا — neutral and very natural
• بكرا بتبلش الفترة التجريبية — emphasizes tomorrow
• رح تبلش الفترة التجريبية بكرا — explicitly future

In everyday Levantine, subject-first word order is very common, but other orders are also normal.

A standard MSA version would be:

تبدأ الفترة التجريبية غدًا
or
الفترة التجريبية تبدأ غدًا

Main differences:

• Levantine بلّش vs. MSA بدأ
• Levantine بكرا vs. MSA غدًا
• Levantine often uses the present marker بـ in forms like بتبلش

So the Levantine sentence is clearly everyday spoken Arabic, while the MSA version is more formal and written.