Research suggests that dogs have some understanding of human communication, but the extent of their comprehension is still not fully understood. Dogs are able to recognize certain words and phrases, and they may also be able to understand the tone of a person's voice. However, it is not clear whether dogs truly understand the meaning of human language in the same way that humans do. Some studies have shown that dogs are capable of understanding a few hundred words, while others suggest that dogs are more attuned to nonverbal cues, such as body language and facial expressions. Overall, it seems that dogs are able to pick up on certain aspects of human communication, but the extent of their understanding is likely limited compared to that of a human.