The DisCoCat framework applies categorical quantum mechanics to natural language processing. The types of a pregroup grammar are interpreted as quantum systems, i.e. as objects of a dagger compact category. The grammatical derivations are interpreted as quantum processes, e.g. a transitive verb takes its subject and object as input and produces a sentence as output. Function words such as determiners, prepositions, relative pronouns, coordinators, etc. can be modeled using the same Frobenius algebras that model classical communication. This can be understood as a monoidal functor from grammar to quantum processes, a formal analogy which led to the development of quantum natural language processing.