يتبل صديقي الصلصة بالبهارات.

Because Arabic often uses verb–subject–object order, especially in Modern Standard Arabic.

So the structure here is:

• يتبل = seasons
• صديقي = my friend
• الصلصة = the sauce
• بالبهارات = with spices

This word order is very normal in MSA.
You could also say صديقي يتبل الصلصة بالبهارات. That version is also correct, but it puts a little more focus on my friend.

In fully vocalized MSA, it would be يُتَبِّلُ.

A native English speaker may be confused because normal Arabic writing usually leaves out:

• short vowels
• the shadda (the doubling mark)

So يتبل is the unvocalized spelling, but the intended pronunciation is yutabbilu.

This is the imperfect form of the verb تبّل meaning to season / spice.

In Arabic, the imperfect usually covers meanings like:

• he seasons
• he is seasoning
• he seasons regularly / habitually

The exact English translation depends on context.
So يتبل does not only mean one tense in the English sense.

Because the verb tells you only the basic grammatical information:

• 3rd person
• masculine
• singular

So يتبل by itself means something like he seasons.

But it does not tell you who he is.
That is why Arabic adds صديقي = my friend.

So:

• يتبل = he seasons
• يتبل صديقي = my friend seasons

صديقي means my friend.

It is made of:

• صديق = friend
• ـي = my

So literally it is friend + my.

This attached ـي is a possessive suffix, and it is very common in Arabic:

• كتابي = my book
• بيتي = my house
• صديقي = my friend

There are a few clues:

1. Word order
   In a normal verbal sentence, the order is often:

   • verb
   • subject
   • object

2. Meaning
   It makes natural sense that my friend is doing the action, and the sauce is receiving it.

3. Case, if fully written
   In full vocalization, the direct object would be الصلصةَ with accusative -a.
   The subject would be nominative, although in صديقي that case ending is not visibly shown because of the ـي suffix.

So the sentence is understood as:

• يتبل = does the action
• صديقي = the doer
• الصلصة = what is being seasoned

Because it has الـ, the Arabic definite article, meaning the.

So:

• صلصة = sauce / a sauce
• الصلصة = the sauce

Here Arabic is talking about a specific sauce, not just any sauce in general.

Here بـ means with / by means of / using.

So:

• بـ = with, by, using
• البهارات = the spices
• بالبهارات = with the spices / with spices

Arabic often uses بـ for the thing used to perform an action:

• كتب بالقلم = he wrote with a pen
• يتبل بالبهارات = he seasons with spices

Also notice that بـ is attached directly to the next word in writing.

Because بـ is more natural here for the idea of using something as an ingredient or means.

• بـ often means with/by using
• مع often means with/together with

So:

• يتبل الصلصة بالبهارات = he seasons the sauce with spices
• مع البهارات would sound more like together with the spices, which is not the usual phrasing for this action

In this sentence, بـ is the more idiomatic choice.

It is plural.

• بَهار = a spice
• بَهارات = spices

So بالبهارات means with spices.

In actual usage, بهارات can sometimes function a bit like a collective noun, similar to how English uses spice or spices depending on context.

It is in the genitive case because it comes after the preposition بـ.

If fully vocalized, it would be:

• بِالْبَهَارَاتِ

That final -i sound is the genitive ending.

So in full form, the sentence would be approximately:

يُتَبِّلُ صديقي الصلصةَ بالبهاراتِ

Because normal Arabic writing usually leaves out short vowels.

So learners often see:

• يتبل صديقي الصلصة بالبهارات

instead of the fully vocalized version:

• يُتَبِّلُ صديقي الصلصةَ بالبهاراتِ

Also, صديقي is a special case because the ـي possessive suffix hides the normal case ending, so the case is understood from grammar, not clearly shown in spelling.

Yes.

The Arabic imperfect form يتبل can often correspond to several English possibilities, including:

• my friend seasons the sauce with spices
• my friend is seasoning the sauce with spices
• my friend seasons the sauce with spices regularly

Context tells you which English translation is best.