أعرف عمر الطفل.

أعرف means I know.

It is the 1st person singular form of the verb عرف (to know). Grammatically, it is in the imperfect form, which in Modern Standard Arabic often expresses the present tense.

So in this sentence, أعرف = I know.

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

In أعرف, the prefix أ- tells you the subject is I.

So Arabic says:

• أعرف = I know

and does not need أنا unless the speaker wants extra emphasis:

• أنا أعرف عمر الطفل = I know the child's age / I do know the child's age

Here, عمر means age.

This is a very common point of confusion, because the same unvowelled spelling عمر can also represent the name ʿUmar.

The difference is in the vowels and the context:

• عُمْر = age / lifetime
• عُمَر = Umar (the male name)

In this sentence, because of the meaning and structure, it clearly means age.

Because the speaker knows the age, not the child.

The structure is:

• أعرف = I know
• عمر الطفل = the child's age

So the whole noun phrase عمر الطفل is the object of أعرف.

In other words, the sentence means:

• I know [the child's age].

It does not mean:

• I know the child, age...

Because this is an iḍāfa construction, often called a possessive construction or genitive construction.

In عمر الطفل:

• عمر = age
• الطفل = the child

Together they mean:

• the age of the child
• more naturally in English: the child’s age

In an iḍāfa:

1. the first noun usually does not take الـ
2. the second noun is in the genitive
3. the whole phrase can still be definite

So even though عمر has no الـ, the full phrase عمر الطفل is definite because الطفل is definite.

Because it is the second part of an iḍāfa.

In Arabic, when two nouns are linked like X of Y, the second noun is put in the genitive case.

So:

• عمرُ الطفلِ = the age of the child

In fully vowelled, careful MSA:

• عُمُرَ الطِّفْلِ in this sentence as the object phrase
  • عمرَ is accusative because it is the direct object of أعرف
  • الطفلِ is genitive because it is the second noun in the iḍāfa

In fully inflected MSA, عمر is the direct object of أعرف, so it takes the accusative case.

That gives:

• أعرفُ عُمُرَ الطفلِ

The ending on عمر is fatḥa because it is mafʿūl bihi (direct object).

So, in careful reading:

• أعرفُ = I know
• عُمُرَ = ageَ / the ageَ
• الطفلِ = of the childِ

In everyday spoken reading, many learners first encounter the sentence without saying the case endings aloud, but they are still important in formal grammar.

A careful MSA pronunciation is:

aʿrifu ʿumra al-ṭifli

A rough breakdown:

• أعرف = aʿrifu
• عمر = ʿumra here, because it is accusative
• الطفل = al-ṭifli

A few pronunciation notes:

• ع is the letter ʿayn, a sound English does not have
• ط is an emphatic t
• the l in الـ is pronounced here, because ط is a moon-letter? Actually ط is a sun letter, so in connected pronunciation it is commonly assimilated: aṭ-ṭifli

So an even more precise connected pronunciation is often:

aʿrifu ʿumra ṭ-ṭifli

But many learner materials still write it as al-ṭifli.

Because Arabic commonly allows and often prefers starting a verbal sentence with the verb.

So:

• أعرف عمر الطفل = literally know-I the child’s age

This is perfectly normal Arabic word order.

Since the subject I is already built into the verb أعرف, there is no need to add a separate subject noun or pronoun.

The most natural translation is I know the child’s age.

The verb عرف can have different shades of meaning depending on context, including to know, to recognize, or to become acquainted with, but in this sentence the intended meaning is clearly to know a piece of information.

So the best translation here is simply:

• I know the child’s age.

Yes, but أعرف عمر الطفل is the most straightforward form.

For emphasis, Arabic might move things around, such as:

• عمرَ الطفلِ أعرفُ = The child’s age, I know
• أنا أعرف عمر الطفل = I know the child’s age with emphasis on I

But for a neutral statement, أعرف عمر الطفل is the normal and simple choice.