Breakdown of Ella desata el nudo para abrir el paquete misterioso.
ella
she / her (after a preposition)
para
for / in order to (+ infinitive) / by (a deadline)
abrir
to open
el paquete
the package
Questions & Answers about Ella desata el nudo para abrir el paquete misterioso.
How would I use the grammar from this lesson to say "She must be untying the knot"?
You would use debe de followed by an infinitive. To say "She must be untying", you combine it with the continuous form: Ella debe de estar desatando el nudo. If you just wanted to say "She must untie it" as a logical assumption, you would say Ella debe de desatar el nudo. Remember that deber de expresses probability, while deber without de expresses obligation.
Is the verb desata related to the Spanish word for "to tie"?
Why do we use para instead of por before abrir here?
We use para because it expresses a goal or purpose. When you mean "in order to" do something, you always use para followed by an infinitive verb like abrir. If you used por, it would incorrectly suggest she untied the knot "because of" opening the package, rather than in order to open it.
Could I say el misterioso paquete instead of el paquete misterioso?