Both ´Veya´ and ´Yada´ mean ´or´.

Can they be used in exactly the same context?

1) Do you want tea or water?

2) Or do you prefer ayran?

1) could ofcourse also be translated with ´Çay mı Kahve mi içersin/istersin?, but i´m after the ´or´ solution.

Çay mı Su mı içersin/istersin

yes, they mean the same, but first of all, ya da is written separately, or one might think it is a typo and you were trying to write yağda... the second thing is, you can use like

either come with me or go with him

ya benimle gelirsin, ya da onunla gidersin

çay ya da kahve içmek ister misin?

would you like to have a cup of tea or coffee?

bir şey içmek ister misin? çay, kahve veya / ya da portakal suyu?

Would you like to drink something? Tea, coffe or orange juice?

Veya is also known as veyahut, which the youngsters don´t use it very often//

Thanks Merih,

So the ya da is used in constructions like Or....., or...

But what about the ´veya´

You´ll have to answer it, as we´re the only two logged in!

Sorry, you already answered it

yoksa would be better for questions;

Çay mı yoksa kahve mi istersin?

Yoksa ayran mı tercih edersin?

The differences in meaning are very slight. Disclaimer: I´m not a turk, only someone who´s learning turkish, so take my advice with a few grains of salt.

It seems like veya is used when you only have a few options.

- Çey veya kahve içmek ister misiniz? - Do you want to drink tea or coffee? - There are no other options is the subtext here.

Whereas ya da is more open ended

- Çay mı ya da kahve mi ister misiniz? - Do you want tea or coffee? - You can ask for anything along the lines of tea or coffee but those are all worth mentioning, all that come to mind.

Çay veya kahve içmek ister misiniz?

This is usually shortened as

Çay kahve ister misiniz?

in colloquial language.

Çay mı yada kahve mi istersiniz?

This is usually shortened as

Çay mı kahve mi istersiniz?

And implicitly means (Tea or Coffee? No other choice.)