A lányok addig beszéltek, hogy enni muszáj, míg vegül ettem egy kis levest. This is a quote from story in a textbook. After every story there's a small vocabulary. There's an interesting comment against word "muszáj": "muszáj (using this word is not recommended) -must (from German word muss sein)" Why is it not recommended to be used? Is it obsolete? In which cases should it be used? Thanks!