Tetrillo says she thinks discomfort is at the root of this problem.

"[The Portuguese-speaking customers] are just afraid to ask for what they want in English," she says. "They feel a little embarrassed to talk."

But there are some who are angered by the language barrier, says East Cambridge resident Shannon Larkin.

"It's unfortunate, but I have seen some conflict. The Portuguese tend to stick together, to gravitate into a small community and choose not to mix," Larkin says.

A few English-speaking residents became upset when a recently opened medical clinic trained its employees to answer the phones in Portuguese rather than English, Larkin says.

"It seemed like a small issue to me," she says, "but it does show some tension."

Roselia Jaquerano, who came to the U.S. from El Salvador 15 years ago and owns a boutique in East Cambridge, says that she has not found the tension to be quite so subtle.

"When I opened my store here, people told me I was so lucky because the Portuguese never give opportunities [to other nationalities] on Cambridge Street," she says.