Up until the last week of school, Ofelia Martinez drilled her students on spelling. Especially tricky were words like “knight” with letters hidden in plain sight.

“You’re going to have here some words that are spelled with ‘kn,’ but you don’t hear the ‘k,’ you just hear the n sound,” Martinez said.

Many of her students at Milam K-8 Center in Hialeah are from Cuba and are still learning English.

Yet nearly all of them were graded the same as native English speakers on the state’s standardized exams this year, and their scores will count toward the state-issued letter grades for schools, due out soon. Previously, students had two years of English instruction before their scores were counted. Now they only have one.

It is one of a slate of changes, including a tougher grading scale on the Florida Comprehensive Assessment Test.

Miami-Dade schools are bracing for the impact. The change is expected to drag down grades for schools like Milam, which currently has a B, but more than 90 percent of its students are still learning English.

Schools that get failing marks miss out on bonus money and can lose students to other campuses. Teachers can see the impact, too, since student scores will drive half of their evaluations this year — and eventually their pay.

“The research tells us that for a student to demonstrate mastery in other subjects like math or science, it takes three to five years of language instruction,” said Miami-Dade Schools Superintendent Alberto Carvalho. “Depriving students of that time and forcing them to take an exam that can count against them I think it is not logical but it is punitive to the child, to the school, to the teachers and to the district.”

Florida Education Commissioner Gerard Robinson proposed the rule as part of his effort to win Florida a waiver from No Child Left Behind. The federal law mandates students must meet benchmarks, or schools suffer consequences, like replacing teachers or restructuring academics. The Obama administration offered waivers for states to avoid the harshest consequences last year after federal lawmakers failed to rework the education law.

But when it comes to students learning English, experts and bilingual education advocates argue there are less punitive ways to hold schools accountable for their progress.

Roberto Martinez, vice chairman of the State Board of Education, has appealed to high-ranking administrators with the U.S. Department of Education to try to get the rule changed.

“I’m not satisfied that it cannot be changed. I’m not satisfied the federal government cannot be persuaded. So I’m not finished pursuing this issue,” Martinez said. The deadline for attaining a waiver is July 15.

Carvalho has said the district, with other groups, might explore legal options because a group of students could be “disproportionately impacted.”

Nearly 19 percent, or 68,000 students, in Miami-Dade are considered “English-language learners.” That is more than other large districts, such as Broward with 25,000 such students, or about 10 percent.

“It’s not fair to say a student has learned math or hasn’t learned math ... on the basis of results of a test that’s written in a language that they can’t understand. That would be like asking me to take a test in Urdu,” said Rosa Castro-Feinberg, a member of the League of United Latin American Citizens’ state education commission, which has asked Gov. Rick Scott to change the new rule. “It would not reflect my knowledge of anything other than my lack of knowledge of Urdu.”