بما أن الموعد النهائي غدا، يقرأ المتدرب استمارة التسجيل اليوم.

بما أن means since, because, or given that. It introduces the reason for the main action.

So the sentence structure is basically:

• بما أن الموعد النهائي غدا = Since the deadline is tomorrow
• يقرأ المتدرب استمارة التسجيل اليوم = the trainee reads the registration form today

In fully vocalized Arabic, this is often written بما أنَّ. In normal unvowelled text, the shadda is usually not shown.

In Arabic, the verb to be is usually omitted in the present tense.

So:

• الموعد النهائي غدا literally looks like the deadline tomorrow
• but it means the deadline is tomorrow

This is very normal in Arabic nominal sentences.

Compare:

• الموعد النهائي غدا = The deadline is tomorrow
• كان الموعد النهائي أمس = The deadline was yesterday
• سيكون الموعد النهائي غدا = The deadline will be tomorrow

So Arabic only needs an explicit be verb when the sentence is in the past or future, or when extra emphasis is needed.

Here غدا means tomorrow, and it functions as an adverb of time.

A more fully marked spelling is غدًا, but short vowels and tanwīn are usually not written in everyday Arabic text, so غدا is very common.

It does not need الـ and it does not need a preposition like في in this sentence.

So:

• غدا = tomorrow
• اليوم = today

Both can act directly as time expressions.

The Arabic imperfect tense, like يقرأ, can cover several meanings depending on context:

• reads
• is reading
• will read

In this sentence, the time word اليوم and the reason clause make the meaning clear: the trainee is doing this today because the deadline is tomorrow.

So English might translate it in different ways depending on style:

• The trainee reads the registration form today
• The trainee is reading the registration form today
• The trainee will read the registration form today

Arabic often leaves this kind of nuance to context instead of marking it as strictly as English does.

Because Arabic often uses verb–subject–object order in verbal sentences.

So:

• يقرأ المتدرب استمارة التسجيل = The trainee reads the registration form

This is a very common MSA pattern.

You can also say:

• المتدرب يقرأ استمارة التسجيل

That is also correct, but it feels a little different in emphasis. Starting with the subject can make the trainee feel more like the topic of the sentence.

So both are possible:

• يقرأ المتدرب... = more standard verbal-sentence order
• المتدرب يقرأ... = subject first, often slightly more emphatic or topical

Because these are two different grammar patterns.

الموعد النهائي is noun + adjective:

• الموعد = the appointment/date
• النهائي = final

In Arabic, adjectives agree with the nouns they describe in definiteness, so if the noun has الـ, the adjective also has الـ:

• الموعد النهائي = the final date / the deadline

But استمارة التسجيل is an iḍāfa (construct phrase), meaning something like form of registration:

• استمارة = form
• التسجيل = the registration

In an iḍāfa, the first noun usually does not take الـ, even when the whole phrase is definite.

So:

• الموعد النهائي = noun + adjective
• استمارة التسجيل = iḍāfa

As a whole, استمارة التسجيل is definite, even though استمارة does not have الـ.

That is because in an iḍāfa, the definiteness of the whole phrase depends on the second noun.

Since التسجيل is definite, the entire phrase is definite:

• استمارة التسجيل = the registration form

This is a key point for English speakers: the first noun in an iḍāfa usually does not take الـ, but the whole phrase can still mean the ....

A fully vocalized version could be:

بما أنَّ الموعدَ النهائيَّ غدًا، يقرأُ المتدرّبُ استمارةَ التسجيلِ اليومَ.

Here is what is happening:

• أنَّ makes its noun accusative
• الموعدَ النهائيَّ = the noun and its adjective, both accusative
• غدًا = adverb of time
• يقرأُ = imperfect verb in the indicative
• المتدرّبُ = subject, nominative
• استمارةَ = direct object, accusative
• التسجيلِ = genitive, because it is the second term of an iḍāfa
• اليومَ = adverb of time, often accusative

In normal printed Arabic, these endings are usually omitted, so learners have to infer them from grammar rather than spelling.