Bu değerlendirmenin nesnel olduğunu düşünüyorum.

It comes from değerlendirme, which means evaluation, assessment, or appraisal.

Here it appears as değerlendirme + nin → değerlendirmenin.

The ending -(n)in is the genitive ending, often corresponding to of or marking possession/association.

So on its own, değerlendirmenin means roughly:

• of the evaluation
• or, in this sentence’s grammar, the evaluation’s

Because değerlendirme ends in a vowel, the genitive takes the buffer n, giving -nin.

Because this sentence contains an embedded clause: that this evaluation is objective.

In Turkish, when a clause like that is turned into a noun-like structure, the subject of the embedded clause usually takes the genitive ending.

So:

• Bu değerlendirme nesnel. = This evaluation is objective.
• Bu değerlendirmenin nesnel olduğunu düşünüyorum. = I think that this evaluation is objective.

In the second sentence, bu değerlendirme becomes bu değerlendirmenin because it is the subject of the embedded -DIK clause.

Turkish usually does not use a separate word exactly like English that here.

Instead, the idea of that this evaluation is objective is expressed by the structure:

• bu değerlendirmenin nesnel olduğunu

So the that-clause is built into the grammar of the sentence, especially through olduğunu.

You can think of:

• nesnel olduğunu = that it is objective

So there is no separate word for that; Turkish packages it into the clause itself.

Olduğunu is a very common Turkish form, and it is built from several pieces:

• ol- = to be / become
• -duk / -dık / -duğu type nominalizing suffix
• -u = a possessive/agreement ending
• -nu = accusative after a possessed form

More practically, in this sentence:

• nesnel olduğunu = that it is objective

A useful breakdown is:

• ol-duğ-u-nu

This is one of the standard ways Turkish turns a full statement into a noun-like clause that can become the object of another verb such as düşünmek.

Because nesnel is an adjective meaning objective.

In a simple main sentence, Turkish can often leave out an explicit verb to be:

• Bu değerlendirme nesnel. = This evaluation is objective.

But inside a noun clause like I think that..., Turkish usually needs a verbal form to carry the clause grammar. That is where ol- comes in.

So:

• nesnel = objective
• nesnel olduğunu = that it is objective

This does not necessarily mean become objective here. In this structure, ol- often functions like the missing to be.

No. That is a very common confusion.

Even though olduğunu looks like it contains oldu, it does not automatically make the meaning past in this kind of structure.

For example:

• Haklı olduğunu düşünüyorum. = I think that he/she is right.
• not I think that he/she was right

So in Bu değerlendirmenin nesnel olduğunu düşünüyorum, the meaning is present-time in English:

• I think this evaluation is objective

The tense of these embedded forms is often understood from context rather than translated mechanically as past.

Because the whole embedded clause is the object of düşünüyorum.

The clause is:

• bu değerlendirmenin nesnel olduğu = the fact that this evaluation is objective

When that clause becomes the direct object of düşünüyorum, it takes the accusative ending:

• olduğu → olduğunu

The n is a buffer consonant that appears before case endings after possessed forms.

So:

• olduğu = that it is
• olduğunu = that it is as a direct object of the main verb

Because Turkish often uses the -yor form for things English expresses with a simple present.

So:

• düşünüyorum can mean I am thinking
• but very often it also means I think

With mental-state verbs like düşünmek, this is extremely normal.

So in this sentence:

• düşünüyorum = I think

not necessarily a temporary I am in the middle of thinking right now.

The sentence is:

• Bu değerlendirmenin nesnel olduğunu düşünüyorum.

Structure:

• Bu değerlendirmenin = of this evaluation / this evaluation’s
• nesnel olduğunu = that it is objective
• düşünüyorum = I think

So the literal logic is something like:

• I think [this evaluation’s being objective].

More natural English:

• I think that this evaluation is objective.

This is very typical Turkish word order: the entire embedded clause comes before the main verb.

Yes. A simpler alternative is:

• Bence bu değerlendirme nesnel.

That means:

• In my opinion, this evaluation is objective.

This is simpler because it avoids the embedded-clause structure.

The difference is roughly:

• Bu değerlendirmenin nesnel olduğunu düşünüyorum. = I think that this evaluation is objective.
• Bence bu değerlendirme nesnel. = In my opinion, this evaluation is objective.

Both are natural, but the original sentence is a very useful pattern because it teaches you how Turkish says I think that..., I know that..., I believe that..., and so on.