يبدأ التحقيق اليوم.

Because Arabic often uses a verb–subject word order, especially in straightforward news-style or formal statements.

So:

• يبدأ التحقيق اليوم = Begins the investigation today = natural English: The investigation begins today

You could also say:

• التحقيق يبدأ اليوم

This is also correct, but it gives the sentence a slightly different feel, with more focus on the investigation itself. In Modern Standard Arabic, starting with the verb is very common.

يبدأ means he begins, it begins, or simply begins, depending on context.

In this sentence, it refers to التحقيق (the investigation), which is a masculine singular noun, so يبدأ means:

• it begins
• more naturally in English: the investigation begins

Arabic present-tense verbs often cover both simple present and near future, depending on context. Here, with اليوم (today), it means begins today.

Because its subject, التحقيق, is a masculine singular noun.

• التحقيق = the investigation
• It is grammatically masculine and singular
• So the verb is also masculine singular: يبدأ

This is normal agreement in Arabic.

Also, when the verb comes before the subject, Arabic commonly uses a singular verb even if the subject is plural. In this sentence the subject is already singular, so there is no extra complication.

The verb comes from بدأ meaning to begin.

Useful forms:

• بدأ = he began
• يبدأ = he/it begins
• ابدأ = begin! (command to one male)
• بداية = beginning

The root is ب د أ.

This is a hamza verb, so the final ء is part of the root.

A careful pronunciation is approximately:

• yabda'u

Breakdown:

• يَ = ya
• بْ = b
• دَ = da
• ءُ = a glottal stop with u

In normal pausing pronunciation, learners often hear something close to yabdaʼ.

Important point: the final ء is a real consonant, a hamza (glottal stop), not just a spelling symbol.

Because الـ is the Arabic definite article, meaning the.

So:

• تحقيق = an investigation / investigation
• التحقيق = the investigation

In this sentence, we are talking about a specific investigation, so the definite form is used.

التحقيق is pronounced approximately:

• at-taḥqīq

The ل of الـ is not pronounced here because ت is a sun letter.

So instead of pronouncing it as al-taḥqīq, Arabic doubles the t sound:

• written: التحقيق
• pronounced: at-taḥqīq

This is a very common pattern in Arabic.

اليوم means today.

Here it functions as an adverb of time, telling you when the action happens:

• يبدأ التحقيق اليوم
• The investigation begins today

Arabic often places time expressions like اليوم, غدًا, أمس after the main part of the sentence, though placement can vary.

It can feel like either, depending on context, but in English the most natural translation is usually:

• The investigation begins today

Arabic present tense can cover:

• present actions
• habitual actions
• near future actions

Since today points to a scheduled event, English often uses the simple present too:

• The investigation begins today

You could also understand it as:

• The investigation is starting today

Yes, in full formal Arabic there are case endings, though they are often not pronounced in everyday reading or speech.

A fully inflected version would be:

• يبدأُ التحقيقُ اليومَ

Explanation:

• يبدأُ = verb with final u
• التحقيقُ = subject of the verb, so nominative
• اليومَ = adverbial accusative of time

In most ordinary contexts, especially for learners, these endings are often omitted in pronunciation.

Yes, that is grammatically possible, but it is less neutral.

• يبدأ التحقيق اليوم = the most straightforward and natural order
• يبدأ اليوم التحقيق = puts more emphasis on today

Arabic word order is flexible, and moving اليوم earlier can add focus or stylistic emphasis.

It is the subject.

Even though it comes after the verb, it is still the thing that performs or undergoes the action of beginning:

• يبدأ = begins
• التحقيق = the investigation

So the sentence structure is:

• verb + subject + time expression

This is very common in Arabic.

Yes. Depending on context, تحقيق can mean things like:

• investigation
• inquiry
• verification
• realization / fulfillment in some contexts

But with التحقيق in a sentence like this, the most natural meaning is usually the investigation.

Context always decides the best translation.