"My backpack is in the subway."
Translation:Мой рюкзак в метро!
Мой is 'my' when talking about a masculine thing so мой рюкзак, мой друг, but not мой жена. As far as I have gotten in the course I have never encountered Мог. If you meant Мои or Моя or мое then Moi is for 'my' plural, so мои яблоки, моя is for feminine, моя жена, and Мое is for neuter, мое место.
why is it so very difficult to get and use the Russian keyboard? Can there not be a Russian keyboard underneath the English one? I often do know what the words mean or I know the Russian word but can't work out how to write what I know I want to write because the Russian keyboard isn't on the same page as the exercise
It depends if you are using an android phone or iphone. Or maybe you're using a PC i dont know but i can answer for android.
You basically have to go to settings and search "language" there you probably find language input and you click and find "Русский" (i think) and that enables you type Russian on your phone like i just did with Русский.
Hope that helps. But sorry if it doesnt.