Duolingo, a United States-based edtech unicorn, will increase its investments in China's online language learning market this year to cash in on the robust long-term growth potential in the country.

"We are optimistic about the long-term prospects in the China market," said Xiang Haina, marketing director of Duolingo China. "China is one of our key markets and we will invest more on growing users, brand building, course development, products research and localization."

The e-learning startup offers a language-learning app that utilizes mini games to test the reading, listening, writing and speaking skills of users and provides audio and vocabulary examples related to real life. It especially caters to casual learners or those who are complete beginners and like to try out different languages.

Duolingo app saw rapid growth last year and became one of the leading e-learning apps. The company saw a 300 percent growth in new users during the March-April period, compared to 67 percent growth in global users during the same period a year earlier, according to the 2020 Duolingo Language Report.

"There is a growing interest among Chinese people for learning various foreign languages. Due to the COVID-19 effect, a large number of people who found themselves stuck at home started turning to mobile apps to kill time. Our Duolingo app proved to be a hit for those who wanted online learning at that time," said Xiang.

Currently, Duolingo app offers 39 languages, including six courses customized for the China market, namely in English, Spanish, Japanese, Korean, French and Italian. Chinese users can choose Chinese as the starting language to learn on the app, said officials.

With an eye on Chinese users' increasing demand for language learning, Duolingo will upgrade the current entry-level content and offer high-level courses. In addition, the company will also launch a Cantonese course this year.

"China is now among the top six countries with the largest number of active users. This year, we will continue improving our current user base, including attracting more users living in the second-and third-tier cities in China," said Xiang.

Launched in 2011, Duolingo app has over 500 million users in 195 countries and regions across the world. Last November, the e-learning company said it raised $35 million from a Series H round of financing from a group of investors led by Durable Capital Partners LP and General Atlantic. The company said it would use the funds for product research and development as well as team expansion.

According to Xiang, Duolingo's revenues are mainly from subscription fees, advertising and its Duolingo English Test, which gained huge following among Chinese students. China had the largest number of Duolingo English Test candidates last year, she said.

Duolingo English Test is used as a proof of students' English language proficiency for applying to universities overseas. Students are able to finish the online English exam anytime and anywhere in one hour and get the results in two days. Currently, over 3,000 institutions in the world accept the test, including top universities like Imperial College London, University College London and the University of Hong Kong.

A report by iiMedia Research predicted that the value of China's online education market would exceed 450 billion yuan ($69.7 billion) by the end of 2020, up 9.61 percent year-on-year.