He spoke with her lawyer's receptionist for twenty minutes yesterday is a sentence asked to be written in German. I wrote it as "Er hat gestern zwanzig Minuten mit der Sekretar ihrer Anwaltin gesprochen (I can't type umlauts for some reason in Commons) but the answer given is Er hat gestern zwanzig Minuten mit der Sekretar seiner Anwaltin gesprochen. This doesn't seem right because that means He spoke with his lawyer's receptionist for twenty minutes yesterday.