No formal notion of markedness has been advanced for syntactic-semantic features of language. A hypothesis is presented which states that if all related features are defined as comprising sets, then it is possible to predict the occurrence of a member of a set by the absence of any other member of the set. Any lexical item subcategorized for gender will be specified, for example, as being feminine or it will carry no gender specification at all. This hypothesis is supported with evidence from Spanish (1) loan words, (2) nominalized lexical items, (3) compound verb forms, and (4) first and second plural personal pronouns. The process of neutralization characterizing gender specification is defined as two conflicting features merging into one (the unmarked) when the underlying structures predict the use of both. A logical correlation in markedness between syntax and morphology frequently exists. Morphologically unmarked elements are used in more syntactic situations than their marked counterparts. Among the situations from Spanish cited are: (1) the replacement of "le" by "se"; (2) the use of the less morphologically marked present tense syntactically to replace the imperfect, preterite, and future; and (3) the use of the (unmarked) singular form of nouns to indicate mass and abstract nouns. (JK)