This document discusses animal communication and how it compares to human language. It outlines several key properties of human language, including reflexivity, displacement, arbitrariness, productivity, and cultural transmission. While some animals can communicate, their systems have limitations and do not demonstrate true language. Research with great apes that were taught sign language provided some evidence of language abilities, but their communication remained limited. The parrot Alex provided the best evidence that an animal may acquire elements of language, as he learned hundreds of words and could use them productively in novel combinations. However, animal communication systems differ fundamentally from human language.