The waiter with dreadlocks and a Bob Marley T-shirt glides among a group of chic Jordanians sipping cappuccinos and smoking hookahs, or water pipes.

A call to prayer from a distant mosque is drowned out by the sound system playing rock band Coldplay and the lively chatter of young customers: "What's up? Keefak?", "Thank you, habibi."

The banter is a form of speech that mixes Arabic with English. It is widely used among Jordan's Western-educated elites, drawing ire from language purists and exposing a widening social and economic gap in the small kingdom.

Dubbed by some Arabizi - a slang term for Arabic and Inglizi, English in Arabic - it is also a means of expression for many young Jordanians who have been educated abroad and who do not share Jordan's conservative values.

"When I came back from university in Canada I realised that everybody was mixing English and Arabic. It is so prevalent. It wasn't like that five years ago," said Dalia Alkury, 25, author of an independent documentary called Arabizi.

"It is easier to express yourself in English about topics that are considered taboo, like sex. I can't speak about sex with my friends in Arabic. The words are too heavy and culturally loaded. It all sounds 'haram' (sinful). I feel more free in English. Arabizi is a way to escape taboos," she said.

Linguists blame the growing use of English among young Jordanians on American pop culture inundating the Arab world.

"Some young people look down on Arabic language. They think it is old and that English represents life and desires," said Haitham Sarhan, a linguist and professor at Jordan University.

"If this trend continues Arabic could be in danger. Young people think Arabic is boring," Sarhan said.

He said the trend was an example of an intellectual crisis in Arab countries, which was outlined in a United Nations Arab Human Development report published earlier this year.

Mixing Arabic with foreign languages has long been commonplace among Western-educated elites in Arab countries such as Lebanon or Algeria.

In cosmopolitan Beirut, young people sometimes greet each other with a salutation that mixes English, Arabic and French: "Hi, Keefak, Ca va?"

But in Jordan, a poor desert country, the sudden popularity of Arabizi reflects deep changes in society since the early 1990s, when authorities embarked on economic liberalisation programmes.

An influx of white-collar workers and professionals from Kuwait during the 1991 Gulf War and from Iraq in more recent years created a more affluent and liberal middle-class.

Pupils at private and public schools study English from a young age in Jordan, a moderate and pro-Western state ruled by King Abdullah, who was educated in England and in the United States.

But elite schools in wealthy neighbourhoods in Amman, where Arabizi is spoken at trendy cafes and American-style malls, teach many of their subjects, like sciences, in English.

In the gritty working-class areas of East Amman or in the tribal heartland, Arabizi is unheard of and few speak English.

Moosa Shteiwi, a sociology professor at Jordan University and director of Jordan's Centre for Social Research, said the use of English language has become a status symbol among middle and upper-class Jordanians, many of whom send their children to universities in the United States.

"It's an expression of class position and works as a demarcation of social status. It is a way of putting a cultural distance between you and the pastoral and Bedouin world of traditional Jordan," Shteiwi said.

"It's a new phenomenon. The lines between the rich and the poor are becoming more evident as we move towards a class society.

In the past the upper classes belonged to the government's bureaucracy. The new class is not shy about showing off its status and English is just another sign of status."

Arabizi, the documentary, will be broadcast on state-run Jordanian television early next year.

It tackles the use of Arabizi through a series of interviews, sometimes showing Arabic-speaking parents sitting next to their Arabizi-speaking children.

Alkury said she speaks Arabic at home with her parents.

Even though she uses English or Arabizi most of her day, she said she is proud of her heritage and of her mother tongue, Arabic.

"I speak Arabizi all day but I feel very Jordanian. If I was going to write poetry, I could only do it in Arabic."