Even as Shanghai strives to be a more international city, locals insist that its unique dialect must be saved to preserve its cultural identity. Pessimistic linguists and cultural experts have warned that Shanghainese, a dialect that few people from other parts of the country understand, is showing signs of dying out as Putonghua and English gain ground amid an influx of mainland and global talent. Shanghai dialect, which differs from Putonghua in its tones and vocabulary, was once essential to learn for an outsider hoping to live in the city. Non-locals living in Shanghai tried to grasp the dialect because the natives would look down on them if they spoke Putonghua in shops, restaurants and offices. The local dialect also used to be a symbol of Shanghai chauvinism and was partly to blame for the city's fraught relationship with other parts of the country. In other mainland cities, people would be upset if two Shanghai people spoke the dialect in public. But the Shanghainese-speaking population has been decreasing since 1985, when a new law was introduced requiring local schools to adhere strictly to teaching in Putonghua as part of a policy of promoting linguistic unity. The role of the Shanghai dialect was further dented in the 1990s when the city stepped up its efforts to become a world-class metropolis. Shanghai people attributed the declining popularity of the local dialect to the booming economy, with thousands of other mainlanders and expats moving to the city. A study by Shanghai's Academy of Social Sciences found that only 60 per cent of pupils in local primary and junior middle schools were able to speak the local dialect. Only a few were fluent and anecdotal evidence showed that some children of native parents were not able to speak a single word of Shanghainese. As the local dialect fades away, worries about the threat its decline poses to Shanghai's unique culture are mounting among locals. Their increasing awareness of the need to protect their dialect has been reflected in the success of Shanghai comedian Zhou Libo , whose Shanghai-dialect talk shows over the past four years have struck a chord with millions of locals. In 2011, a group of young people, mostly university students, launched a campaign to promote the local dialect. The group, called Hu Cares, gathers at the People's Square every week, calling on people to preserve the Shanghai dialect. The word Hu is the short form of Shanghai in Chinese. Their efforts attracted the attention of local education authorities, who introduced the dialect in music and art lessons in the September semester and provided students with new textbooks featuring poems and folk songs in Shanghainese. As Shanghai tries to preserve its cultural identity, it must strike a balance between local pride and its international ambitions. For a long time, Shanghai people referred to those from other parts of the mainland as "country folk", reflecting the sense of superiority among Shanghainese who lived in the mainland's most affluent city. Unlike people in Guangdong, who insist on Cantonese's superiority because it has a richer linguistic history than Putonghua, educators in Shanghai suggest that outsiders learn Shanghainese because a command of the local dialect will make them more confident residents of the city.