Can you, please, explain to me how you came up with YOUR pronunciation of Savanna—which sounds to me as with 4 syllables rather than 3—"Safananna"—I mean that superfluous "NAN" ???
The audio is not correct, like many on this course on Duolingo.
The audio is created by a speech machine and not a real speaker. This is why it has lot of mistakes in it.
The pronunciation is incorrect, as is the case with many other pronunciations in this course. I can't blame machines here as I can clearly tell it was a human who pronounced it and probably another checked/edited it. A human with an accent too.
Shouldn't this be يسكن instead because Bob is a man?
This is true for 3rd singular male person
but here we have 2nd singular male person (Bob), hence it is تسكن (taskun)