Ablam gelince birlikte kahve içeceğiz.

Ablam means my older sister.

It breaks down like this:

• abla = older sister
• -m = my

So ablam is literally older sister-my.

A useful detail: abla specifically refers to an older sister, not just any sister. Turkish often distinguishes older siblings in everyday vocabulary.

Because Turkish usually shows possession with a suffix attached to the noun.

So instead of saying something like my older sister with a separate word, Turkish says:

• abla = older sister
• ablam = my older sister
• ablan = your older sister
• ablası = his/her older sister

This is very common in Turkish.

Gelince means when she/he comes, once she/he comes, or upon coming, depending on context.

It comes from:

• gel- = come
• -ince / -ınca = a suffix meaning when or once

So:

• gelince = when/once he, she, or it comes

In this sentence, it refers to ablam, so the meaning is when my older sister comes.

Because Turkish often leaves subjects unstated when they are clear from context.

In Ablam gelince, the noun ablam already tells you who is coming. So Turkish does not need an extra word for she.

Literally, it is more like:

• My older sister when-comes

Natural English: When my older sister comes

Because the verb ending already contains both the future tense and the we subject.

It can be broken down like this:

• iç- = drink
• -ecek = future tense suffix
• -iz / -ğiz = we

So:

• içeceğiz = we will drink

Turkish verbs often include the subject, so a separate biz (we) is not necessary unless you want emphasis.

The dictionary form is içmek = to drink.
To make the future tense, Turkish removes -mek and adds the future suffix:

• iç-
  • -ecek → içecek = will drink

Then it adds the we ending:

• içecek
  • -iz → içeceğiz

The spelling and pronunciation shift slightly in the combined form, giving içeceğiz.

So the whole form means we will drink.

Because Turkish verbs usually make the subject clear on their own.

İçeceğiz already means we will drink, so biz is optional.

You could say:

• Ablam gelince birlikte kahve içeceğiz.
• Ablam gelince biz birlikte kahve içeceğiz.

The second one is more emphatic, like we will drink coffee together.

Birlikte means together.

In this sentence, it modifies the action of drinking coffee:

• birlikte kahve içeceğiz = we will drink coffee together

Turkish word order is fairly flexible, but this placement is very natural.
You may also hear similar words like beraber, which can often mean the same thing in everyday speech.

Here kahve is an indefinite object, so it appears without the accusative ending.

• kahve içeceğiz = we will drink coffee

This is similar to a general or non-specific object in Turkish.

If the object were specific, Turkish might use the accusative:

• kahveyi içeceğiz = we will drink the coffee

So the version in your sentence sounds like we’ll have coffee / drink coffee, not we’ll drink that specific coffee.

The sentence follows a very common Turkish pattern:

• Ablam gelince = when my older sister comes
• birlikte kahve içeceğiz = we will drink coffee together

So the structure is roughly:

[time clause] + [adverb] + [object] + [verb]

Turkish often places the main verb at the end, which is why içeceğiz comes last.

Yes, in many contexts Turkish speakers could also say ablam geldiğinde.

Both can mean when my older sister comes/when my older sister has come, but there can be small differences in style and nuance.

• gelince often feels compact and very common for when/once she comes
• geldiğinde can sound a bit more explicitly like when she is in the state of having come or when she arrives

For a learner, gelince is a very natural and common way to express when she comes in this sentence.

Not always.

Its basic meaning is older sister, but Turkish speakers also use abla as a polite or warm way to address or refer to an older young woman, a bit like big sis in tone.

In ablam, though, the most natural reading is my older sister unless context suggests otherwise.