The meaning in language emerges through an interaction between the potential meaning of the words themselves (such as the things that the word “ate” can mean) and the meaning of the grammatical construction into which they are plugged. For example, even though “sneeze” is in the dictionary as an intransitive verb that only goes with a single actor (the one who sneezes), if one forces it into a ditransitive construction — one able to take both a direct and indirect object — the result might be “She sneezed him the napkin,” in which “sneeze” is construed as an action of transfer (that is to say, she made the napkin go to him). The sentence shows that grammatical structure can make as strong a contribution to the meaning of the utterance as do the words. Contrast this idea with that of Chomsky, who argued there are levels of grammar that are free of meaning entirely.

The concept of the Swiss Army knife also explains language learning without any need to invoke two phenomena required by the universal grammar theory. One is a series of algebraic rules for combining symbols — a so-called core grammar hardwired in the brain. The second is a lexicon — a list of exceptions that cover all of the other idioms and idiosyncrasies of natural languages that must be learned.

The problem with this dual-route approach is that some grammatical constructions are partially rule-based and also partially not — for example, “Him a presidential candidate?!” in which the subject “him” retains the form of a direct object but with the elements of the sentence not in the proper order. A native English speaker can generate an infinite variety of sentences using the same approach: “Her go to ballet?!” or “That guy a doctor?!” So the question becomes, are these utterances part of the core grammar or the list of exceptions? If they are not part of a core grammar, then they must be learned individually as separate items. But if children can learn these part-rule, part-exception utterances, then why can they not learn the rest of language the same way? In other words, why do they need universal grammar at all?