I am just a learner also but as far as I know the letter 'כ' has two possible sounds. It will be pronounced with either a 'k' or 'kh' depending on the word, its position in the word, and its conjugation.
I spelled it with an "alef" like this:
הגבר בורח מכאן
And it was marked CORRECT though i thought the translation would be "the man is running away from HERE" rather than FROM YOU which i would think is ממך