Language acquisition involves structures, rules and representation. The capacity to successfully use language requires one to acquire a range of tools including phonology, morphology, syntax, semantics, and an extensive vocabulary. Language can be vocalized as in speech, or manual as in sign. Human language capacity is represented in the brain.

Even though human language capacity is finite, one can say and understand an infinite number of sentences, which is based on a syntactic principle called recursion.

Evidence suggests that every individual has three recursive mechanisms that allow sentences to go indeterminately.

These three mechanisms are:

1. Coordination --> Compound Sentences (IC1 +, coordinator + IC2)

2. Subordination --> Complex Sentences (IC + DC); (DC + (C)

2.1 Relativization --> relative/adjectival clauses

2.2 Complementation --> complement clauses

In the previous lesson (Four Types of Sentences), we learned about compound sentences, which are formed through coordination.

In essence, a compound sentence is composed of two independent clauses (IC) linked by a coordinating conjunction/coordinator (i.e., for, and, nor, but, or, yet, so).

E.g., I love coffee, but I also like tea. { IC1} +, coordinator + {IC2}

In a compound sentence, both independent clauses are finite, meaning that they have tensed verbs. The verbs in the two independent clauses are also required to be consistent.

E.g., I love coffee, but I also like tea. (Both 'love' and 'like' are in the present tense.)

With respect to relativization and complementation, both are realized through dependent clauses. Specifically, relativization is realized through relative clause and complementation through complement clauses.

We are going to look them next.