Yo ví (I saw) ---> Me gusta éste, pero prefiero ése. en un lecion en una web pagina aqui pero... "Me gusta esto, pero prefiero eso" <---¿es correcto verdad?

I'll try to help. éste and ése are demonstrative pronouns: They mean "this one" and "that one" respectively in the masculine form. esto and eso are also demonstrative pronouns but they mean "this" and "that" respectively *in the singular neuter form only* (used to refer to unknown objects). So "me gusta éste, pero prefiero ése" means "I like this one, but I prefer that one", and is grammatically correct. esto and eso are only used to replace unknown objects or abstract situations. Eg. Qué es esto? What is this? (unknown object) Esto es bueno. This is good (referring to a situation) http://spanish.about.com/od/pronouns/a/demonstrative_pronouns.htm That article explains it quite well Hope this helps