Arkadaşım masasında kitap okuyor.

Arkadaşım is made of:

• arkadaş = friend
• -ım = my

So arkadaşım means my friend.

In Turkish, possession is often shown by adding a suffix directly to the noun instead of using a separate word like my.

Because Turkish usually puts possessive meaning into a suffix.

So instead of saying something like my friend with two separate words, Turkish commonly says:

• arkadaşım = my friend

You can say benim arkadaşım, but that is usually more explicit or emphatic, like my friend as opposed to someone else’s friend. In an ordinary sentence, arkadaşım is enough.

Masasında can be broken down like this:

• masa = desk/table
• -sı = his/her/its
• -n- = buffer consonant
• -da = in/on/at

So:

• masa-sı-n-da = at/on/in his/her desk

In natural English, this is often understood as at his/her desk or on his/her desk, depending on context.

That -n- is a very common buffer consonant in Turkish.

It appears when a noun already has a 3rd-person possessive ending like -sı / -si / -su / -sü, and then another case ending is added.

So:

• masa = desk
• masası = his/her desk
• masasında = at/on/in his/her desk

Without the buffer n, the word would be awkward to pronounce. This pattern is very common in Turkish.

The Turkish locative ending -da / -de is broader than any one English preposition.

With masa it can be translated in different ways depending on context:

• at the desk
• on the desk
• sometimes even in the desk if the situation clearly requires that

In this sentence, the most natural understanding is usually at his/her desk.

Yes, most naturally it does.

Because the subject is arkadaşım and the noun masasında has a 3rd-person possessive ending, the usual interpretation is:

• my friend ... at his/her desk

Turkish often leaves this kind of relationship implicit. You do not need to repeat his/her own unless you want special emphasis.

A bare noun like kitap often gives a non-specific meaning.

So kitap okuyor is something like:

• is reading a book
• is doing some book-reading

It does not strongly point to one particular book.

If you say bir kitap okuyor, that makes the object more clearly a book / one book. Both are possible, but the version without bir is very common in Turkish.

In Turkish, direct objects are often treated differently depending on whether they are specific/definite or non-specific.

• kitap okuyor = reading a book / books / book in a general non-specific sense
• kitabı okuyor = reading the book / a specific book

So the lack of an accusative ending here tells you the object is non-specific.

This is a very important Turkish pattern:

• bare object = usually non-specific
• accusative-marked object = usually specific/definite

Okuyor comes from the verb oku- meaning to read.

The ending -yor is the common Turkish marker for an ongoing or current action, often called the present continuous.

So:

• oku-yor = is reading / reads

In this sentence, it most naturally means an action happening now: is reading.

Because Turkish normally prefers Subject–Object–Verb word order, and the verb often comes last.

This sentence follows a very normal Turkish pattern:

• Arkadaşım = subject
• masasında = location
• kitap = object
• okuyor = verb

So the final verb position is completely standard in Turkish, even though it feels different to an English speaker.

Yes, Turkish word order is flexible, but different orders change the emphasis.

For example, this sentence is neutral and natural. Other orders are possible if you want to emphasize a particular part, such as the location or the object.

However, okuyor will very often stay at the end in ordinary statements.

So for learners, this sentence is a good model of basic Turkish sentence structure.

This is because of vowel harmony and suffix variation.

Turkish suffixes often change their vowels to match the vowels in the word they attach to.

For example:

• -ım / -im / -um / -üm are versions of the same possessive suffix
• -da / -de are versions of the same locative suffix

So:

• arkadaşım uses -ım
• masasında uses -da

These are not different meanings—just the correct harmonic forms of the same suffixes.

It can mean both table and desk, depending on context.

So masasında could theoretically mean:

• at his/her desk
• at his/her table
• on his/her desk/table

In this sentence, if the intended meaning shown to you is about a desk, then that is the correct reading here. But it is good to know that masa is broader than English desk alone.