Arkadaşım da ben de parkta çay içiyoruz.

The ending -ım is a possessive suffix meaning my.

• arkadaş = friend
• arkadaşım = my friend

Turkish usually adds possession directly to the noun instead of using a separate word like my.

Similar examples:

• ev = house
• evim = my house

So arkadaşım da starts with my friend too / my friend as well.

In this sentence, da/de means too / also, and it is used after each part of the pair:

• Arkadaşım da = my friend too
• ben de = I too

Together, this gives the sense of both my friend and I.

So Turkish often builds this kind of coordination with repeated da/de, where English would usually use and.

A very literal sense would be:

• My friend too, I too, are drinking tea in the park.

Natural English: My friend and I are drinking tea in the park.

Because ben is the subject of the sentence, so it stays in the basic form.

• ben = I
• beni = me
• benim = my / of me

Here, I am one of the people doing the action drinking, so Turkish uses ben.

• Arkadaşım da ben de... = My friend and I...

If you said beni, that would make me an object, which would not fit here.

No. They look similar, but they are different things.

1. da/de after arkadaşım and ben is a separate word meaning too / also.

   • It is written separately: ben de

2. -ta/-te/-da/-de in parkta is a case ending meaning in / at / on.

   • It is written attached: parkta

So:

• ben de = I too
• parkta = in the park

This is a very common point of confusion for learners.

This is the locative case, which means in / at / on.

The basic suffix is often shown as -DA, but its actual form changes.

In parkta:

• park ends in k, which is a voiceless consonant
• after a voiceless consonant, d becomes t
• the vowel is a because of vowel harmony

So:

• park + ta = parkta = in the park

Compare:

• evde = in the house
• okulda = at school
• parkta = in the park

Because Turkish often leaves nouns bare when the meaning is general or obvious from context.

• çay = tea
• bir çay = a tea / one tea
• çayı = the tea / tea as a definite object

In this sentence, çay içiyoruz simply means we are drinking tea. It sounds natural and general, like talking about the activity rather than a specific cup.

English often needs an article or some determiner, but Turkish often does not.

İçiyoruz breaks down like this:

• iç- = drink
• -iyor- = present continuous / ongoing action
• -uz = we

So:

• içiyoruz = we are drinking

This matches the subject arkadaşım da ben de, because my friend and I together count as we.

Because any subject that includes I plus someone else is treated as we.

So:

• ben = I
• arkadaşım + ben = my friend and I
• therefore the verb takes the 1st person plural ending: -uz

This is the same idea as English:

• I am drinking
• but my friend and I are drinking

In Turkish:

• içiyorum = I am drinking
• içiyoruz = we are drinking

The sentence follows a very normal Turkish pattern:

• Arkadaşım da ben de = subject
• parkta = place
• çay = object
• içiyoruz = verb

So the structure is roughly:

Subject + Place + Object + Verb

Turkish very often puts the verb at the end.

English is less flexible here, but Turkish can move parts around for emphasis. For example, Parkta arkadaşım da ben de çay içiyoruz is also possible, with extra focus on in the park.

Because they are different grammatical elements.

• da/de meaning too / also is written as a separate word
• the locative -da/-de/-ta/-te meaning in / at is a suffix, so it is attached

So:

• ben de = I too
• parkta = in the park

This spelling difference is important in Turkish.

Turkish does have words like ve for and, but with people in this kind of sentence, repeating da/de is very natural.

So instead of:

• Arkadaşım ve ben...

you often get:

• Arkadaşım da ben de...

This has a sense like my friend too, and I too → my friend and I.

Both are understandable, but the version with repeated da/de is very common and natural in everyday Turkish.

A very literal version would be:

My friend too, I too, in the park, tea are-drinking.

That sounds strange in English, but it helps show how Turkish is built.

A natural English translation is:

My friend and I are drinking tea in the park.

So it is better to understand the Turkish grammar pattern rather than translate each word one by one.