After visiting many Chinese cities, Sears learned more about China and ancient Chinese culture. He said when he came to China in the last century, few Chinese could speak good English. However, English education has been popularized across the country in recent years.

Similarly, Chinese language and culture were mysterious and not known by people in most countries, but now, more and more people in the world are learning Chinese, even Chinese history, traditional Chinese medicine and so on, Sears added.

At present, the 70-year-old American has made his home in China with his friend's support. Apart from taking part in some social activities, Sears devotes all his efforts to the study of Chinese characters.

Since the end of last year, Sears has been working with a Chinese technology company on a smartphone application for children to learn about how the characters evolved. The app, which shows the step-by-step evolution of the first batch of 108 characters with augmented reality technology, is expected to be launched on June 1.

"When I die, I hope my website will live on, and I'm planning to write a book about my research. This will be my gift to China," he said.