صاحبي تبنى الجرو.

Yes—both can mean my friend.

• صاحبي is very common in everyday Levantine speech.
• صديقي is understandable, but it often sounds more formal or closer to Standard Arabic.

So in casual spoken Levantine, صاحبي often feels more natural.

Depending on context, صاحبي can also mean something like my buddy, my male friend, or sometimes even my boyfriend, but in this sentence it means my friend.

The -ي is the possessive suffix meaning my.

So:

• صاحب = friend / companion
• صاحبي = my friend

This is a very common pattern in Arabic. For example:

• صاحبك = your friend
• صاحبه = his friend
• صاحبها = her friend

تبنى is a past-tense verb meaning he adopted.

More specifically, it is:

• 3rd person
• masculine
• singular

So it matches صاحبي, which is a masculine singular subject.

It is pronounced roughly tabannā.

A few important points:

• The final ى is not pronounced like y here.
• It represents a final long ā sound.
• So the word ends in -nā, not -ni.

Also, in normal Arabic spelling, short vowels are usually not written, so learners have to know the pronunciation from context or from prior study.

Because that is very normal in spoken Levantine.

So:

• صاحبي تبنى الجرو = My friend adopted the puppy

This subject-first order is extremely common in conversation.

A verb-first version is also possible in Arabic, but in Levantine everyday speech, subject-first often sounds more natural.

Yes. الجرو means the puppy.

That is because الـ is the definite article, like the in English.

• الجرو = the puppy
• جرو = a puppy / puppy

Arabic does not usually use a separate word for a/an, so the noun without الـ is often indefinite.

It gets pronounced fully here.

That is because ج is a moon letter, not a sun letter. So the l sound of الـ stays.

So the article is pronounced something like il- or el-, depending on region.

In other words, this is not like words where the l disappears through assimilation.

No. It does not tell you whether the speaker is male or female.

It tells you that the friend is grammatically masculine.

So both a man and a woman could say صاحبي if they mean my male friend.

If you wanted my female friend, you would usually say:

• صاحبتي

So:

• صاحبي تبنى الجرو = my male friend adopted the puppy
• صاحبتي تبنّت الجرو = my female friend adopted the puppy

Because this is how Arabic is normally written in everyday use, especially for dialects like Levantine.

A learner should know two things:

• Short vowels are usually not written.
• Case endings belong to Standard Arabic grammar and are not normally used in spoken Levantine.

So a Levantine sentence like this is written in a simple, practical way, and the reader supplies the pronunciation from familiarity with the language.