Teyzem gelince birlikte çay içeceğiz.

Teyzem means my maternal aunt.

It breaks down like this:

• teyze = maternal aunt
• -m = my

So teyzem literally means my aunt.

A useful cultural/language note:

• teyze = mother’s sister
• hala = father’s sister

Turkish often builds possession directly onto the noun instead of using a separate word like my.

Gelince comes from the verb gelmek = to come.

Here, -ince / -ınca is a common ending meaning:

• when
• once
• as soon as

So teyzem gelince means when my aunt comes or once my aunt comes.

This form is very common for linking one action to another:

• Eve gidince ararım. = When I get home, I’ll call.
• Seni görünce sevindim. = I was happy when I saw you.

Because gelince is not the main verb of the sentence. It creates a time clause: when she comes.

Compare:

• Teyzem geliyor. = My aunt is coming.
• Teyzem gelecek. = My aunt will come.
• Teyzem gelince... = When my aunt comes...

So gelince doesn’t mean simply comes by itself. It means when she comes and sets up the timing for the main action.

Because the main action has not happened yet.

İçeceğiz breaks down as:

• iç- = drink
• -ecek / -acak = future
• -iz / -ğiz = we

So içeceğiz = we will drink.

The sentence describes a future plan or expected action:

• first, my aunt comes
• then, we will drink tea together

Because Turkish verbs already show the subject.

In içeceğiz, the ending tells you the subject is we.

So Turkish often leaves out pronouns when they are already clear from the verb ending.

• içeceğim = I will drink
• içeceksin = you will drink
• içecek = he/she/it will drink
• içeceğiz = we will drink

You can add biz for emphasis:

• Biz teyzem gelince birlikte çay içeceğiz.

But it is not necessary.

Birlikte means together.

It is an adverb, so it describes how the action happens:

• birlikte çay içeceğiz = we will drink tea together

It can often move around in the sentence without changing the basic meaning much:

• Teyzem gelince birlikte çay içeceğiz.
• Teyzem gelince çay içeceğiz birlikte.
  This is less neutral, but possible in speech.
• Teyzem gelince çayı birlikte içeceğiz.

The original sentence sounds natural and neutral.

Turkish does not use articles like a, an, and the the way English does.

So çay can simply mean tea, and the exact sense depends on context.

In this sentence, çay içeceğiz is a natural way to say we will drink tea.

If you wanted to make it more specific, Turkish has other ways:

• bir çay = a tea / one tea
• çayı = the tea (specific object, marked)

But in a general sentence like this, plain çay is normal.

The sentence follows a very typical Turkish pattern:

• Teyzem gelince = time clause
• birlikte = adverb
• çay = object
• içeceğiz = main verb

So the overall order is roughly:

When my aunt comes + together + tea + we will drink

Turkish usually puts the main verb at the end.

A very common pattern is: time expression + object + verb

So this sentence is quite natural and standard.

Usually no. Gelince normally means when she comes or once she comes, not if she comes.

If you want if she comes, Turkish usually uses gelirse:

• Teyzem gelirse birlikte çay içeriz. = If my aunt comes, we drink / we’ll drink tea together.

So:

• gelince = when / once
• gelirse = if

That is an important distinction.

Yes. Teyzem geldiğinde birlikte çay içeceğiz is also possible.

Both gelince and geldiğinde can mean when my aunt comes in this kind of sentence.

Very roughly:

• gelince = simpler, very common, often like when / once
• geldiğinde = also when, but a bit more structurally explicit, sometimes slightly more formal or more tied to a specific occasion

In everyday speech, gelince is extremely natural here.

Roughly:

• çay sounds like chai
• içeceğiz starts like ee-cheh-
• the c in Turkish sounds like the j in jam
• ğ is usually soft and often lengthens the vowel rather than making a strong consonant sound

So içeceğiz is roughly like ee-cheh-jee-iz, though the exact sound is smoother in real Turkish pronunciation.

A rough full pronunciation could be:

TEY-zem geh-LIN-jeh beer-LIK-teh chai ee-cheh-JEH-eez

Not perfect English-style spelling, but close enough to help.