Sen gelene kadar burada duracağım.

Yes, it can often be omitted if the context already makes it clear who is coming.

• Sen gelene kadar burada duracağım = explicit you
• Gelene kadar burada duracağım = still possible, but now the listener must figure out from context who is meant

Using sen makes the subject of gelene kadar clear, and it can also add emphasis or contrast, like I’ll stay here until you come, not someone else.

Because sen is the subject of gelene kadar.

In this sentence:

• sen = the person who will come
• ben is understood as the subject of duracağım = I will stay

If you said seni, that would make you the object, which does not fit this structure.

This is a very common Turkish time expression:

• verb stem + -ene/-ana kadar = until ... happens

So:

• gel- = come
• gelene kadar = until someone comes

You usually learn this as a set pattern. Some more examples:

• Ben gelene kadar bekle. = Wait until I come.
• Bitene kadar burada kal. = Stay here until it finishes.

So in your sentence, sen gelene kadar means until you come.

Because in this pattern, the person is usually shown by the separate subject word, not by a personal ending on gelene.

Compare:

• ben gelene kadar = until I come
• sen gelene kadar = until you come
• Ayşe gelene kadar = until Ayşe comes

So the subject is added in front, and gelene kadar itself stays the same pattern.

Durmak can mean several related things, depending on context:

• to stop
• to stand
• to stay / remain

In burada duracağım, the most natural meaning is I will stay here or I will remain here.

In English, that may sometimes be translated as I’ll wait here, but Turkish is focusing more on remaining in that place than on the act of waiting itself.

If you wanted to stress waiting, you could also say:

• Sen gelene kadar burada bekleyeceğim. = I will wait here until you come.

That said, duracağım is perfectly natural if the idea is I’ll stay right here.

Because of a common sound change in Turkish.

The future tense is:

• -acak / -ecek

And first person singular is:

• -ım / -im / -um / -üm

So you might expect:

• duracak + ım

But in Turkish, k often softens to ğ before a vowel in this kind of situation:

• duracak + ım → duracağım

So duracağım means I will stay / I will stand / I will stop, depending on context.

Burada means here.

It is built from:

• bura = this place
• -da = in / at

So literally it is something like in this place or at this place.

Related words:

• burada = here
• orada = there
• şurada = over there

Yes. Turkish word order is flexible.

Your sentence is natural as:

• Sen gelene kadar burada duracağım.

But you could also say:

• Burada sen gelene kadar duracağım.
• Burada duracağım sen gelene kadar.

These versions shift the focus a little, but the basic meaning stays the same.

A time clause like sen gelene kadar often comes early in the sentence, but it does not have to.

They are different time meanings:

• gelene kadar = until you come
• gelince = when / once you come

So:

• Sen gelene kadar burada duracağım. = I will stay here until you come.
• Sen gelince gideceğim. = I will leave when you come.

With gelene kadar, the action continues up to that point. With gelince, the action happens at or after that point.

It can, depending on context.

Because durmak has a range of meanings, burada duracağım could be understood as:

• I will stay here
• I will remain here
• I will stand here

In many everyday situations, English would naturally translate it as I’ll stay here until you come or I’ll wait here until you come, even if the Turkish verb is durmak rather than beklemek.