Protic ionic liquids are salt formed by a Bronsted acid and a Bronsted base. Proton transfer occurs from the acid to the base, creating a complex network of hydrogen-bonded (HB) ions. However, given the complex molecular structure of cations, it is possible to identify protons participating to the HB network depending on the belonging to a given molecular subgroup. This property makes them suitable model systems to characterize competing intramolecular and intermolecular quantum effects. By exploiting selective isotope substitution, it is our aim to characterize nuclear quantum effects in both HB and non-HB protons, as well as their interplay, in the prototype protic ionic liquid ethylammonium nitrate.