MUKILTEO — The growth has been incremental yet ever so consistent.

It can be found on nearly every campus in the Mukilteo School District. The number of students learning English as a second language has increased from 718 in 2000 to more than 3,000 today. The district in recent times has been averaging an additional 143 such students a year, roughly the equivalent of five to six classrooms.

Among them, those students speak 90 languages. The list of new languages this year is worthy of a “Jeopardy” question: Gujarati, Cebuano, Bemba, Ilocano, Kinyarwanda, Oromo, Soninke and Telugu.

Students whose first language is Spanish make up 55 percent of the district’s English Language Learner students. Another 14 percent come from Ukrainian and Russian families, followed by Vietnamese at 5 percent, Arabic at 4 percent and Korean at 3 percent.

In the past five years alone, district enrollment of English Language Learner students has risen from 2,400 to 3,100 this fall. During the same time, the number of ELL teaching positions has grown from 23 to 31.

Today, nearly one in five students in the district are part of the English Language Learner program, compared to about 5 percent in 2000.

Most are in the lower grades, but they are spread throughout the system.

Seventy percent are in elementary schools. Another 19 percent are in middle school; the other 11 percent attend high school. At Mariner High School, there are roughly 300 ELL students.

It can be particularly challenging for older students, said Tracey Prpich, whose job includes overseeing ELL programs.

“We are seeing some high school kids come in from Central America with no exposure to English,” she said. By that age, “the content and expectations (of high school classes) are so difficult.”

Leslie Clauson is in her 17th year as principal at Horizon Elementary School off W. Casino Road. When she arrived in 2000, there were 84 students in the ELL program. Today that number is close to 375, roughly half the school’s enrollment.

The school’s ELL teachers spend much of their days floating between classrooms to help other teachers with their lessons. The goal is to help the students keep up with their classmates instead of pulling them away so they miss grade-level instruction.

Typically, it can take five to seven years to exit the ELL program. Most of their instruction time will be in the students’ home classrooms. The progression begins with listening, then advances to speaking, reading and finally writing.

Over the years, Horizon ELL teacher Vikki Roberts has seen many students arrive with no English at all. She watches one word become two words. Later, a sentence becomes a conversation. She witnesses the self-conscious become emboldened.

“When that silent period ends, that is pretty amazing,” she said.

The other day, she watched a fourth-grade boy from the Marshall Islands grasp the word and meaning of the word “personification,” the representation of an abstract quality in human form.

In many ways, it was as powerful for her to see him make the connection as it was for him to make the breakthrough. “This is what I love,” she said.

The school relies on ELL students to help one another. When a student from one country arrives, Clauson will check if there are any others who speak the same language, to see if it makes sense to place them in the same classroom.

Megan Fitzpatrick also is an ELL teacher at Horizon. She likes the idea of getting to work with children over many years instead of just one, which is typical of a grade-level teacher. It is satisfying to her to watch the progress over time.

Her colleague Hannah Vlieger sees children from different countries use what little English they have learned to forge friendships in the cafeteria and on the playground. Those friendships, she said, allow their vocabularies to grow and help them toward social independence.

Schools in other parts of Snohomish County also are seeing increasing numbers of ELL students, but few have been at the same rate as Mukilteo. The statewide average grew from 5.9 percent in 2000 to 10.8 percent last year.

Eric Stevick: 425-339-3446; stevick@heraldnet.com.