I have seen sentences ending in "per esercitare"; "da esercitare", and "a esercitare" in this lesson. And I get it wrong every time. Can someone please help me understand when I'm supposed to use "per, da, and a" with infinitives? I've tried to google explanations, but I haven't found a satisfactory answer.
Usually the prepositions that introduce the infinitives are the same that introduce normal objects, with the same purpose; "da" is a little different here because this is a type of object that can only work with a subordinate sentence, and it means "which can be", "which must be". As for the others, in "Vado a esercitarmi" (I go exercise) 'a' has the same meaning as in "Vado a casa" (I go home), while 'per' generally introduces purpose sentences, e.g. "Prendi l'autostrada per tornare a casa" (Take the highway to go back home).
- Facciamo da mangiare = We're making food (We're making something which has the purpose of being eaten)
- Abbiamo da fare = We have stuff to do (We have things which have the purpose of being taken care of)
- Cerco una gonna da comprare = I'm looking for a skirt to buy...
- Cosa c'è da vedere a Parigi? = What is there to see in Paris?...
Does that help a little?