Kim ne derse desin, veterinerin verdiği mama köpeğe iyi geldi.

It is a common concessive expression meaning no matter what anyone says.

Literally, it is built from: kim = who
ne = what
derse = if he/she says
desin = let him/her say

So the literal feel is something like who says what, let them say it. In natural English, that becomes no matter what anyone says.

Because this is a set Turkish pattern used to express concession.

• derse is the conditional form: if he/she says
• desin is a kind of jussive / third-person imperative: let him/her say

Together, X derse desin gives the idea even if X says it, let them say it anyway → no matter what X says.

So Turkish uses both forms to create this emphatic meaning. It is not random repetition.

In this sentence, they are not asking a question. Instead, they function like whoever and whatever.

This is very common in Turkish. Question words can appear in structures that mean:

• kim → whoever / anyone who
• ne → whatever / anything that

So kim ne derse desin does not mean who says what? It means whoever says whatever or more naturally no matter what anyone says.

Veterinerin is the genitive form of veteriner, so it means of the veterinarian or the veterinarian’s.

This happens because verdiği mama is a relative-clause structure, and in this type of Turkish construction, the subject of the relative clause is usually put in the genitive.

So:

• veteriner = veterinarian
• veterinerin verdiği mama = the food that the veterinarian gave

A very similar pattern is:

• adamın yazdığı mektup = the letter that the man wrote

Not exactly. Verdiği is not a normal standalone past-tense verb. It is a relative-clause form built from vermek.

It means something like that he/she gave in: veterinerin verdiği mama = the food that the veterinarian gave

A useful way to think of it is:

• ver- = give
• -diğ- = part of a relative/nominalized form
• -i = agreement/possessive ending used in this structure

So verdiği behaves more like an adjective modifying mama than like the main verb of the sentence.

Because the visible noun mama belongs to the main clause, not directly to the relative clause.

Inside the relative clause, mama is understood as the object of verdiği:

• the food that the veterinarian gave

But in the full sentence, mama is the subject of the main verb iyi geldi:

• the food ... did the dog good

In Turkish relative clauses, the head noun usually appears in the form required by the main clause, not by its role inside the relative clause.

So here:

• inside the relative clause: mama is the thing given
• in the main clause: mama is the subject

That is why it appears as plain mama, not mamayı.

Because the expression iyi gelmek takes the dative case.

So:

• köpeğe = to the dog

The structure is:

• birine iyi gelmek = to be good for someone, to help someone, to agree with someone

Examples:

• Bu ilaç bana iyi geldi. = This medicine did me good.
• Temiz hava ona iyi geldi. = Fresh air did him/her good.

So köpeğe iyi geldi means it was good for the dog.

Word-for-word, yes, it looks like came well, but that is not the real meaning here.

İyi gelmek is an idiomatic expression meaning:

• to do someone good
• to be good for someone
• to agree with someone
• to help someone feel better

So in this sentence, köpeğe iyi geldi means that the dog benefited from the food, not that something physically came well.

The sentence has two main parts:

1. Kim ne derse desin
   a fronted concessive clause: no matter what anyone says

2. veterinerin verdiği mama köpeğe iyi geldi
   the main clause: the food the veterinarian gave was good for the dog

A rough structural breakdown is:

• Kim ne derse desin = concessive opener
• veterinerin verdiği mama = noun phrase, with the relative clause before the noun
• köpeğe = dative object of iyi gelmek
• iyi geldi = main verb at the end

This is very normal Turkish word order:

• subordinate material first
• modifiers before the noun
• main verb last

The comma separates the introductory concessive clause from the main clause.

So:

• Kim ne derse desin, = introductory idea: no matter what anyone says,
• the rest gives the actual statement

In English, we often do the same thing:

• No matter what anyone says, the food the vet gave was good for the dog.

So the comma helps show that the first part sets the frame, and the second part carries the main message.