in our language we do not say letter 'w' this sound is not .there is not...bizim alfabemizde böyle bir harf yok buyüzden iki harfide okurken aynı sesle okuruz.

They are two different letters, with completely different sounds in English. In German and Polish they have a similar sound, but in English they are completely uninterchangeable. You couldn't, for example, write "wan" instead of "van".