But after nine months of hard study, he was fluent.

"I was soon offered an interview with Gameloft, one of the world's largest mobile gaming companies. The fact I could talk fluently in English during the job interview was one of the reasons I was offered a job as a programmer," he said.

For employers, putting up language requirements is one of the very first steps to screen candidates. Take a quick look at the job advertisements posted on 51job.com for example, basic requirements set up by the leading multinational companies for fresh graduates is always something like "fluent English and good communication skills".

If it is with more senior positions, such as a department manager, the requirement will come higher to "excellent spoken and written English". Undoubtedly, these positions are usually better paid, most of which offer at least 10,000 yuan ($1,639) a month.

According to recruitment service provider BRecruit, candidates with higher English proficiency are always in demand. It highlights changes in the fast-moving consumers goods industry, particularly, as being vastly improved if the candidate can speak English, despite general entry requirements for the sector being low,

It said that ever since the world's leading luxury brands slowed down their growth in China's first-tier cities, the industry has been facing with a brain-drain especially for those with good language and management skills. As a result, luxury brand companies are having to poach staff from the hotel industry, a sector traditionally rich with English-speaking young staff.

According to the 2014 China Salary Report compiled by human resources service provider Randstad, professionals with both Chinese and English proficiency are in big demand in the financial services industry; while another report released last month by global recruitment specialist Hays found a surge in demand for bilingual staff by the information technology industry also.

Interestingly, the EF report noted that average English proficiency declined among Hong Kong adults between 2007 and 2013, although they are still above that of Chinese mainland adults, which have been improving, largely as a result of increased spending on language courses by the expanding middle class.

The English language skills of the average Shanghai adults, however, were found to have overtaken those in Hong Kong, with people from Beijing and Tianjin now scoring the same as their Hong Kong counterparts.

Simon Lance, the regional director of Hays in the Chinese mainland, says that despite their catching up, Hong Kong candidates still run a better chance of landing jobs which require English skills, because of their English proficiency.