Bu merhem kaşıntıyı azaltıyor ama biraz pahalı.

Because kaşıntı is the direct object of the verb azaltmak (to reduce), and here it is treated as a specific, definite thing: the itch / this itching.

Turkish often marks a definite direct object with the accusative ending. So:

• kaşıntı = itch / itching
• kaşıntıyı = the itch / the itching (as a specific object)

In this sentence, the ointment is reducing a particular symptom, so the accusative is natural.

The -y- is a buffer consonant.

The noun kaşıntı ends in a vowel, and the accusative suffix here also begins with a vowel. Turkish usually inserts -y- between two vowels to make pronunciation smoother.

So the structure is:

• kaşıntı
• • -ı (accusative suffix)
• becomes kaşıntıyı

This same thing happens in many Turkish words when a vowel-final word takes a vowel-initial suffix.

Because Turkish suffixes follow vowel harmony.

The accusative has several forms:

• -ı
• -i
• -u
• -ü

The last vowel in kaşıntı is ı, so the matching accusative form is -ı. Because the noun ends in a vowel, it becomes -yı with the buffer consonant.

So:

• kaşıntı → kaşıntıyı

Yes, it is the -iyor form, which is often taught as the present continuous, but in real Turkish it is also commonly used for general present situations.

So azaltıyor can mean:

• is reducing
• reduces

In a sentence about what a medicine or ointment does, Turkish very naturally uses -iyor. It can describe a current effect or a general property of the product.

A more formal or more textbook-style alternative would be azaltır, but azaltıyor sounds very natural in everyday speech.

Because in Turkish, the present-tense copula (is/are) is often omitted.

So:

• biraz pahalı literally looks like a little expensive
• but it means it is a little expensive

Turkish does not need a separate word for is in this kind of present-tense sentence.

A fuller, more formal version could be:

• ama biraz pahalıdır

But in normal conversation, ama biraz pahalı is the usual way to say it.

Biraz means a little, a bit, or somewhat.

Here it softens the adjective pahalı (expensive), so the meaning is:

• a little expensive
• somewhat expensive

It makes the statement less strong than simply saying pahalı.

The basic word order is very typical Turkish:

• Bu merhem = subject
• kaşıntıyı = object
• azaltıyor = verb

So the first clause follows the common Turkish pattern:

Subject + Object + Verb

Then:

• ama = but
• biraz pahalı = a predicate adjective phrase

So the whole sentence is structured very naturally for Turkish.

You could, but it would sound less neutral.

The most normal order is:

• Bu merhem kaşıntıyı azaltıyor.

Putting kaşıntıyı after the verb is possible in some contexts, but it usually adds emphasis, sounds marked, or feels less standard in a simple statement like this.

For a learner, the safest pattern is:

Subject + Object + Verb

Yes. Pahalı is an adjective meaning expensive, but in this sentence it functions as the predicate of the clause.

So although it is an adjective, it is doing the job that English often expresses with be + adjective:

• It is expensive → Pahalı
• It is a little expensive → Biraz pahalı

This is very common in Turkish.

The tricky part is the Turkish ı, which is different from English i.

A rough guide:

• ş sounds like sh
• ı is a vowel with no exact English equivalent; it is a neutral, unrounded sound made farther back in the mouth than i
• kaşıntıyı is roughly like ka-shun-tuh-yuh, but that is only an approximation

There are actually several ı sounds in kaşıntıyı, so it can feel difficult at first. The important thing is not to pronounce them like English ee.

Bu means this, so bu merhem means this ointment.

If you said bir merhem, that would mean an ointment / one ointment, which is less specific.

So the sentence is talking about a particular ointment, not ointment in general.

Also, Turkish does not have separate words exactly like English the and a/an in every case. Specificity is often shown through context, words like bu, and object marking such as the accusative.

Yes, that is grammatical.

The difference is mostly one of style and nuance:

• azaltıyor sounds very natural and conversational
• azaltır sounds a bit more general, formal, or like a statement of usual function

And:

• pahalı is normal in everyday speech
• pahalıdır sounds more formal, more written, or more emphatic

So your original sentence sounds more natural in ordinary spoken Turkish, while Bu merhem kaşıntıyı azaltır ama biraz pahalıdır sounds more formal or textbook-like.