Thanks for explaining me , but I don't think so it's same in every language , why because they added extra letters and changed the sounds of few letters . But still I love to learn Spanish . thank you.

It's because in old spanish there used to be a clear difference in the sound of LL and Y, same goes to the sound of V and B a little more recognizable this days than the other but still pretty similar in sound. This leads to a problem in grammar, because is not possible to write all the spanish words by their sound and you have to learn how the words spell to, rather than only how it sounds. But I think that that's goes for all languages, I also have problems to in the same area with the english some times