Apologies if this has been covered before but am at a little bit of loss as to how to phrase search terms to find it. My question is how to phrase “to not have to” versus “must not” so I don’t say one when I mean the other.
The book I ran across this issue in (Barron’s Spanish Pronouns & Prepositions, chapter 4) has the sample sentence: Claudia no debe que comprar el libro. Claudia must not buy the book.
If I wasn't told otherwise, my translation of that sentence would be “Claudia doesn’t have to buy the book,” because in English you say “Claudia doesn’t have to” versus “Claudia has to not” and it seems like the difference is expressed mostly in word order. ñ Wirsing’s Ultimate Phrase Finder (one of my go-to references) has the following sample: Los oficiales de bajo rango no deberan responder por los errors del comandante. The low-level officers should not have to answer for the commander’s mistakes. Okay, now that just muddies it, if you believe both sources then that would mean no deber que can mean either one. How do I be clear?
I was tempted to just go to “no tiene que” instead but then questioned whether that was the same thing. I suppose I could say “no tiene la obligacion de” and that would be clear when I mean not have to, but that doesn’t seem like everyday speech. The machine translators seem to mostly say “no tiene por que” but that doesn’t make sense to me, is that an idiom?
Thanks for any advice, sorry no international keyboard available here