Masanın etrafına sandalyeleri yerleştiriyorum.

Because masanın is the genitive form, meaning of the table.

In Turkish, when you say something like around the table, Turkish often builds it as:

• masa = table
• masanın etrafı = the table’s around / the area around the table

So masanın is needed because etraf is being linked to masa in a possessive-type structure.

etrafına can be broken down like this:

• etraf = around, surroundings
• -ı = 3rd person possessive suffix
• -na = dative ending (to, toward)

So:

• masanın etrafı = the area around the table
• masanın etrafına = to the area around the table / around the table

This is a very common Turkish pattern:

• evin önüne = to in front of the house
• arabanın arkasına = to behind the car
• masanın etrafına = to around the table

Because the verb involves movement or placement toward a position.

• etrafına = to around it / around it → direction, destination
• etrafında = around it / at around it → location

With yerleştirmek (to place, arrange), you are putting something somewhere, so Turkish uses the dative idea:

• masanın etrafına sandalyeleri yerleştiriyorum = I am placing the chairs around the table

If you used etrafında, it would sound more like the chairs are already located there rather than being placed there.

Not exactly. It often behaves more like a noun in Turkish.

That is why Turkish says things in a structure like:

• masanın etrafı = the table’s around / the area around the table

So instead of using a simple preposition the way English does, Turkish often uses a noun + possessive structure for words like:

• ön = front
• arka = back
• üst = top
• alt = bottom
• yan = side
• etraf = around, surroundings

This is why the phrase looks more complex than the English around the table.

Because sandalyeleri is the definite direct object.

Breakdown:

• sandalye = chair
• sandalyeler = chairs
• sandalyeleri = the chairs

Here the speaker is talking about specific chairs, not just chairs in general. Turkish usually marks a specific direct object with the accusative ending.

So:

• sandalyeler yerleştiriyorum would sound wrong here
• sandalyeleri yerleştiriyorum = I’m placing the chairs

Yes, in some contexts sandalyeleri can be ambiguous.

It can mean:

• the chairs
  or
• his/her chairs or
• their chairs

But in this sentence, the most natural meaning is the chairs, because it is functioning as the direct object of the verb.

Context normally makes the meaning clear in Turkish.

yerleştiriyorum means I am placing / I am arranging / I am setting.

It breaks down roughly like this:

• yerleştir- = place, arrange, set
• -iyor = present continuous
• -um = I

So:

• yerleştiriyorum = I am placing

This tense is very common in Turkish for actions happening now.

Because Turkish verbs already show the subject.

In yerleştiriyorum, the ending -um tells you the subject is I.

So Turkish often leaves out pronouns when they are already clear:

• yerleştiriyorum = I am placing
• yerleştiriyorsun = you are placing
• yerleştiriyor = he/she/it is placing

You could say Ben masanın etrafına sandalyeleri yerleştiriyorum, but ben is usually only added for emphasis or contrast.

Turkish usually puts the verb at the end of the sentence.

So the structure here is:

• Masanın etrafına = around the table
• sandalyeleri = the chairs
• yerleştiriyorum = I am placing

That is very normal Turkish word order.

English prefers:

• I am placing the chairs around the table

Turkish prefers:

• Around the table the chairs I-am-placing

Even though that sounds odd in English, it is natural in Turkish.

Yes. Turkish word order is flexible, although some orders sound more natural depending on emphasis.

For example, these can all be possible in the right context:

• Masanın etrafına sandalyeleri yerleştiriyorum.
• Sandalyeleri masanın etrafına yerleştiriyorum.

The second version may feel a bit more neutral to some learners because the object comes earlier, but both are normal.

Changing the order usually changes focus or emphasis, not the basic meaning.

Because they are taking different suffixes for different jobs, and Turkish suffixes change shape because of vowel harmony and sound rules.

• masa + -nın → masanın
  This is the genitive ending.

• sandalye + -ler + -i → sandalyeleri
  This is plural + accusative.

The endings do not always look identical because Turkish adjusts suffixes to fit the sounds of the word.

That is completely normal in Turkish.

Both can involve putting something somewhere, but yerleştirmek often suggests placing or arranging carefully/in an organized way.

• koymak = put
• yerleştirmek = place, arrange, set in position

So in a sentence about chairs around a table, yerleştirmek sounds very natural because it suggests arranging them properly, not just dropping them somewhere.

Yes, but the meaning would change.

For example:

• Masanın etrafına sandalye yerleştiriyorum.

This would mean something like I am placing chairs around the table, with a more general or non-specific sense.

But:

• Masanın etrafına sandalyeleri yerleştiriyorum.

means I am placing the chairs around the table, referring to specific chairs.

So the plural and accusative together help make the sentence more specific.