I am currently going through the Assimil German Language course, and on Lesson 18. There is a part in the dialog that is causing me much confusion. The dialog states:
Oh, das tut mir leid; aber ich bin in fünf Minuten zurück.
Oh, I am sorry; but I will be back in five minutes.
Is it common to express intended future actions, with a state of “being” (bin) in German? Should the verb, werde, be used instead of bin? Or is the Assimil English translation constructed in a way to ease the understanding of English readers?