In spanish "Voltage" (i.e. voltaje) is "tensión" (tension) or "diferencia de potencial" (potential difference). A problem here is that "tension" communicates a concept, but "voltage" communicates nothing, it's only a derivation of the unit used, or perhaps something to do with Alessandro Volta, a gentleman most students these days hadn't the pleasure to meet.

A simmilar problem in spanish was "amperaje" (amperage) which is not much heard any more except very colloquially among electricians; the standard term is "corriente" (current).

However, the units and letters are somewhat confusing for the students:

V(oltage) = E(lectric field?), unit is Volt, is refered as tension of potential differece. A(mp) = I(ntensity), unit is Ampere, is refered as corriente. P(ower), unit Watt, is consistent, as is refered as potencia (power).