Genus
Grammatical gender is a common phenomenon in the world's languages. A typological survey of 174 languages revealed that over one fourth of them had grammatical gender. Gender systems rarely overlap with numerical classifier systems. Gender and noun class systems are usually found in fusional or agglutinating languages, whereas classifiers are more typical of isolating languages. Thus, according to Johanna Nichols, these characteristics correlate positively with the presence of grammatical gender in the world's languages: