Sex workers in Brazil's city of Belo Horizonte, which will host World Cup 2014 semi-finals, are being offered free English lessons to help them welcome the tourist onslaught, officials say.

"They will be learning everyday expressions as well as technical sex vocabulary," said Cida Vieira, who runs the Sex Workers' Association in Minas Gerais state, where Belo Horizonte is the capital.

"They should be able to speak with their clients about fantasies," Vieira stressed.

About 300 prostitutes have already signed up for the classes, she added.

Next on their agenda: expanding the program to include Spanish and French.

"There are 80,000 prostitutes in Belo Horizonte alone. And demand just keeps going up," she said.

Pollyana Temponi, 27-years-old and a three-year veteran of the trade, told the daily "English will be helpful for negotiating prices.... And nowadays, you need English for every job, really."