The past subjunctive in Spanish: -se forms
The most common form of the Spanish past subjunctive is generally the -ara or -iera form mentioned on the previous pages. However, Spanish has an alternative way of forming the past subjunctive, with forms ending in -ase or -iese1. This alternative is formed simply as follows:
Replace -ra with -se, preserving person endings and accents.
This gives forms such as the following:
preguntara > preguntase
llegáramos > llegásemos
tomarais > tomaseis
pidieran > piedesen
dijeras > dijeses
fuera > fuese
Suggest a change / Cambios sugeridos
When do you use the -ara/-iera forms and when do you use the -ase/-iese forms of the past subjunctive?
First, a general rule of thumb:
If in doubt, always use the -ara/-iera forms: they're the most widely used geographically and have the widest possible range of uses.
The -ra form is reported to be more widely used in Latin America and in the Andalucía region of Southern Spain (cf Stewart, 1999, p. 1022). Butt & Benjamin (2000:240) suggest that the -se form is frequent in Argentina.
Whichever is the prevalent form in a particular region, speakers (or at least, literate speakers) are generally exposed to both forms, since in most if not all Spanish-speaking countries, publications from the other countries are widely sold. In Mexico City, for example, the -se forms appear at best extremely rare in speech. But a Mexican reader of Muy Interesante (a popular science magazine published in Spain) will be passively exposed to -se forms even if they wouldn't use those forms actively.
Differences in usage
In terms of meaning, the -ara/-iera forms appear to be used fairly interchangeably. However, a couple of commonly reported differences are:
1. In cases where the past subjunctive form has no i (fuera,
produjera etc), nor does the -se form: fuese,