1. A virtual pet system, comprising: a virtual pet client device including a processor coupled to a memory storing instructions for execution by the processor and a question and answer (Q&A) server device including a processor coupled to a memory storing instructions for execution by the processor, wherein the virtual pet client device is to receive a sentence in natural language and send the sentence and an ID of a pet owner to the Q&A server device; the Q&A server device is to receive the sentence in natural language, process the sentence through natural language comprehension, obtain language characteristics of the pet owner from a pet owner language information base according to the ID of the pet owner, generate an answer in natural language based on a result of natural language comprehensions, reasoning knowledge, and the language characteristics of the pet owner, and send the answer in natural language to the virtual pet client device; wherein the language characteristics of the pet owner include language tips and expression manners.