Universals in formal linguistics
When Chomsky started to develop his generative grammar theory in the late 1950s, the term linguistic universals gained a slightly different meaning. Additionally, it was used to refer to: The underlying principles of linguistic organisation and structures that are represented in the human mind.
This statement embraces the assumption that humans are born with a kind of blueprint grammar; an innate universal grammar that determines what is possible in a language and what is not. Since all humans, according to this view, are born with the same universal set of primitives, for example a restricted set of sounds that they can produce, the number of possible languages must be restricted. Accordingly, the languages of the world must show similar patterns or linguistic universals.
Of course, Chomsky is a nativist in claiming that the principles of UG are innate rather than learned. However, he does not claim that children are born with a fully specified grammar. Children still have to go through the process of acquiring the grammar of the language they are exposed to (i.e. socialisation). Children are quick learners of their mother tongue, which is what led Chomsky to suppose that they must be born with what he calls formal and substantive universals.
Substantive universals are grammatical categories like noun or verb and grammatical functions such as subject or object – you might know these as the basic building blocks of grammar.
Formal universals are then the rules that we use to form meaningful syllables, phrases, sentences. For example, phrase structure rules determine how phrases and sentences can be build up from words. Derivational rules guide the reorganization of syntactic structures such as the transformation from a statement into a question.
Typologists as well as CLs do find this hypothesis problematic since cross-linguistic comparison reveals there to be little evidence for substantive universals of the kind Chomsky assumes.
Categories such as adjectives and grammatical functions like subject or object are apparently not found in all languages.