So, which of the four forms of my should you use in Russian and when:

мой, моя, мои or моё? 

Good question! And the answer is: it depends. It really depends on the Russian nouns you use the word my with. Look at the four columns below. Try to see what the words in each column have in common. (Hint: There is a reason why Russians always pay attention to word endings.) We will learn the rule in the next lesson.