Chat applications using Artificial Intelligence (AI) based on Natural Language Processing (NLP) platforms have been reported to be gradually accepted by people. This research aims to investigate differences between human language processing and Natural Language Processing (NLP) system, which is the core technology of most chat applications, using the synchronized language model. To achieve this objective, this research first distribute and collect questionnaires with questions such as the frequency and motivation of using AI chatbots among university students. The study then evaluate the selected chatbot with linguistic method and knowledge through semantics and pragmatics. Practically, this study proposes valid approaches to perfect existing chatbots. This study suggests that AI chatbots based on NLP can be applied to complete tasks but differ apparently from the human language processing system. The conclusion drawn from this study is that if the AI chatbot is developed to recognize misspelled words and their vocabulary is expanded, it will enhance the applicability of AI chatbots and fit them into people's lives.