Interpreters usually work with oral language. Simultaneous interpretation -- immediately translated from Spanish to English -- is so demanding that very few linguists can do it. Consecutive interpretation -- in which one person speaks and then stops to allow translation -- is more managable. This career requires an exceptional memory and mental dexterity.
Translators typically work with the written word, rather than spoken language. Exceptional analytical ability and writing skills are required to do this job properly. A translator makes slang and colloquialisms understandable to his intended reading audience.
Bilingual editors take translation one step further, and are concerned with accuracy. This linguistic career requires attention to detail, and the ability to ensure that all sections of a publication cover both languages equally.
Another career option for Spanish linguists is teaching the language. A linguist who works at a university typically must hold a master's degree. Those seeking work in elementary and secondary education must obtain a teaching certificate.