Seviche, ceviche? Lemon, lime?

As a fellow who has no facility for foreign language, some things have always been a puzzle. Now the lemon-lime thing has been fairly easy to figure out, mostly. In Mexico a variety of lima is consistently called limon, and in Costa Rica their limon is a green skinned, orange-fleshed lima as best can be determined by me. Real lemons are rather rare throughout Latin America it seems, however, in terms of cuisine, certain varieties of lime and lemon seem to converge and can be used almost interchangeably. Spelling of s/ceviche, and its pronunciation (silent e at the end? each or chay?) has eluded me as have the conjugation of verbs in French and Spanish. But no matter, the combination of fish and citrus juice denatures protein in a very tasty manner. And the Phactor should get busy putting this together for a party later instead of blogging, or he will have to answer to she-who-must-be-obeyed.