الطبيب يفحص المريض.

ال is the Arabic definite article, equivalent to the.

So:

• الطبيب = the doctor
• المريض = the patient

Because both words have ال, both nouns are definite.

Because ط is a sun letter.

With sun letters, the l sound of ال assimilates to the next consonant in pronunciation, even though the spelling does not change.

So:

• الطبيب is written with ال
• but pronounced aṭ-ṭabīb

By contrast, م in المريض is a moon letter, so the l is pronounced normally:

• المريض = al-marīḍ

Yes, this word order is normal.

This sentence is subject–verb–object:

• الطبيب = subject
• يفحص = verb
• المريض = object

Arabic also commonly allows verb–subject–object. So you could also say:

• يفحص الطبيبُ المريضَ

Both are correct in Modern Standard Arabic. The version with the subject first often feels a little more like The doctor is the one who...

يفحص is the imperfect form of the verb, 3rd person masculine singular.

In this sentence it means:

• he examines
• or he is examining

depending on context.

So it matches الطبيب, which is a singular masculine noun.

Because Arabic verbs already contain subject information.

In يفحص, the verb form itself tells you the subject is he:

• يـ at the beginning is the usual marker for 3rd person masculine singular in the imperfect

So Arabic does not need a separate pronoun here. You could add هو, but usually only for emphasis or contrast.

There are two main clues:

• word order
• case endings in fully vocalized Arabic

In ordinary unvocalized writing, word order helps a lot. Here, the sentence is read naturally as:

• الطبيب = subject
• المريض = object

In fully vocalized MSA, the endings make it explicit:

• الطبيبُ يفحصُ المريضَ

Here:

• الطبيبُ has ـُ = nominative, so it is the subject
• المريضَ has ـَ = accusative, so it is the direct object

Because normal Arabic writing usually leaves out short vowels and case endings.

So learners often see:

• الطبيب يفحص المريض

instead of the fully marked version:

• الطبيبُ يفحصُ المريضَ

This is completely normal in books, newspapers, signs, and most everyday texts. Native readers rely on grammar, word order, and context.

It can mean either one.

The Arabic imperfect often covers several English meanings, including:

• examines
• is examining
• sometimes even will examine, if the context makes that clear

So without extra context, يفحص is flexible. If you add something like الآن, it more clearly suggests an ongoing action:

• الطبيب يفحص المريض الآن = The doctor is examining the patient now

Because it is a direct object.

The verb يفحص can take its object directly, just like English examine:

• examine the patient
• يفحص المريض

No extra word like to is needed.

The verb would change to match the subject.

For a female doctor:

• الطبيبة تفحص المريض

For multiple doctors in a subject-first sentence:

• الأطباء يفحصون المريض

So Arabic verbs agree with the subject in person, number, and gender.

The root is ف ح ص.

This root carries the basic idea of examining or inspecting. The verb here is a basic Form I verb.

A useful way to think about it is:

• root: ف ح ص
• dictionary form: فحص
• imperfect: يفحص

Learning roots helps you notice relationships between words and recognize patterns more easily.