Final answer:
The gains made in teaching animals communication have been limited and primarily focus on basic commands.
Step-by-step explanation:
The gains made in the scientific world in trying to teach animals communication have been limited, primarily focusing on basic commands. For example, some animals, such as dogs, have been trained to respond to commands like sit, stay, and come. This kind of training is based on conditioning and does not involve complex language systems comparable to human communication.
Human-reared great apes have demonstrated the ability to use signs or tokens in a rule-based manner to express themselves. This indicates that they have a capacity for what might be considered a proto-language, which is a more simplified form of communication that may have preceded human language. This demonstrates that with proper training, certain animals can exceed basic command recognition and develop more complex forms of communication, albeit still far from the infinite combinatorial potential of human language.