Student fluency woes rising

The number of Boston school students identified as lacking fluency in English surged dramatically over the past school year, presenting further challenges for a school district already under federal investigation for failing to provide adequate programs for students trying to learn the language.

Such students now number nearly 16,000, about 28 percent of the district’s total enrollment, according to new data released by the district. Last fall, the group consisted of more than 11,000 students.

Much of the increase emerged after school officials complied with a federal directive to retest thousands of students who were improperly evaluated over the last seven years for English fluency, causing them not to be identified for services. Those students were tested only on how well they speak and listen in English, but not their ability to read and write in the language.

The retesting effort, carried out over the past six months, identified 4,269 additional students in need of specialized instruction. The students, who have low MCAS scores, run the gamut: Some barely grasp English, while others are almost fluent.