490. ¿Qué opción es la correcta?: We spoke to the school principal. / We spoke to the school principle.

En Estados Unidos se denomina principal a la persona responsable de un colegio, mientras que en Gran Bretaña se le conoce formalmente como headmaster (aunque últimamente se utiliza headteacher o head):

We spoke to the school principle.

We spoke to the school principal.

Principal, acabado en -al (tanto el sustantivo como el adjetivo) significa ‘el más importante’ o ‘alguien que preside’:

Stephen Daniels, PhD, is founder and principal of the school.

Yorkshire’s principal cities are Leeds, Hull, Sheffield and Bradford.

Obesity will be the principal cause of 10 different types of cancer within the next decade.

The principal aim of the research is to establish whether there is a link between these factors.

En finanzas, principal (normalmente en singular) es una inversión o préstamo de dinero o bienes que se realiza con la intención de cobrar intereses:

He tries to keep the principal intact and live off the interest.

Every mortgage payment you make lowers the principal, increasing the home’s equity.

Principle, acabado en -le, solo existe como sustantivo y designa verdades fundamentales o leyes:

We had a lecture on the general principles of the US constitution.

Engineering is essentially the application of both scientific and mathematical principles.

The basic principle behind all these machines is the same.

Estas verdades y leyes a menudo son de carácter moral:

My grandfather was a man of strong religious principles.

We need politicians who are men, and women, of principle.

I refuse to buy their products as a matter of principle.

I am against the death penalty on principle.

In principle se utiliza para expresar acuerdo respecto a una generalización, aunque no entrega o aceptación absolutas, esencialmente porque aún no se conocen todos los detalles de la misma:

In principle I agree with the idea, but I’m not sure it’s worked out well in practice.

The local council says it supports the plan in principle, but needs to study the proposal in more detail.