يشكر صديقي الطبيب.

يشكر is the imperfect verb from شكر to thank.

In this sentence, it means something like:

• he thanks
• he is thanking

In Modern Standard Arabic, the imperfect can cover present-time meanings like simple present and present progressive, depending on context.

Because the verb already includes that information.

يشكر tells you that the subject is:

• 3rd person
• masculine
• singular

So Arabic does not need a separate pronoun here. English says he thanks, but Arabic can simply say يشكر.

This is a very common Arabic word order.

Arabic often uses:

• Verb + Subject + Object

So:

• يشكر = thanks
• صديقي = my friend
• الطبيب = the doctor

That gives My friend thanks the doctor.

Arabic can also use Subject + Verb + Object, but verb-first order is very normal, especially in formal written Arabic.

صديقي means my friend.

It is made of:

• صديق = friend
• ـي = my

So literally:

• صديق + ي = صديقي
• friend + my = my friend

The ending ـي is a possessive suffix.

Because nouns with possessive suffixes are already definite.

So Arabic says:

• صديقي = my friend

not

• الصديقي

Once you add ـي my, the noun is already specific and definite.

Because it means the doctor, not just a doctor.

• طبيب = a doctor / doctor
• الطبيب = the doctor

So the sentence is talking about a specific doctor.

If you wanted a doctor, you would normally use طبيبًا in a fully vowelled sentence.

In the intended reading:

• صديقي = the subject, the one doing the thanking
• الطبيب = the object, the one being thanked

Arabic normally shows this with case endings, but in ordinary writing those short vowels are usually not written.

A fully vowelled version for the intended meaning would be:

• يَشْكُرُ صَدِيقِي الطَّبِيبَ

Here:

• الطبيبَ with -a is the object

Without vowel marks, the written sentence can be ambiguous, but the usual reading here is My friend thanks the doctor.

Yes, in unvowelled writing, that is theoretically possible.

Why? Because Arabic script usually leaves out the short vowels that show case. So:

• يشكر صديقي الطبيب

could also be read with different endings.

For The doctor thanks my friend, the fully vowelled version would be:

• يَشْكُرُ صَدِيقِي الطَّبِيبُ

Here:

• الطبيبُ with -u is the subject

So the bare written form can be ambiguous, and context often resolves it.

Yes. That is also correct.

It uses:

• Subject + Verb + Object

So:

• صديقي يشكر الطبيب = My friend thanks the doctor

This version puts the subject first, which can feel a bit more like English word order and may give slightly more emphasis to my friend.

Both are grammatical:

• يشكر صديقي الطبيب
• صديقي يشكر الطبيب

Because the subject صديقي is singular: my friend.

So the verb must also be singular masculine.

If the subject were feminine or plural, the verb form would change accordingly.

For example:

• تشكر صديقتي الطبيب = My female friend thanks the doctor

So يشكر matches a masculine singular subject.

For the intended meaning My friend thanks the doctor, it would be:

• يَشْكُرُ صَدِيقِي الطَّبِيبَ

A helpful pronunciation guide is:

• yashkuru ṣadīqī aṭ-ṭabība

A couple of notes:

• ال in الطبيب is pronounced aṭ- here because ط is a sun letter
• at the end of a pause, the final short vowel is often not pronounced, so you may hear:
  • yashkuru ṣadīqī aṭ-ṭabīb