My Russian text books put a lot of effort into explaining how to pronounce the Russian vowels а э ы о у, both in stressed and unstressed positions, and also what they sound like after soft consonants, ie as я е и ё ю. They fail to mention what these vowels sound like if you put a й after them.

So I am wondering, do all these combinations exist? ай эй ый ой уй яй ей ий ёй юй? Do they sound different in stressed and unstressed positions?