The Associated Press

LOS ANGELES - Sergio Sanchez came to the United States five years ago from Mexico but is still embarrassed to speak English. Unlike his older brothers, who immigrated when they were young children and are bilingual, the 17-year-old said it has been a struggle to learn the language and go to school.

"It's difficult to pronounce the words, and people laugh... . If I were younger, it would be easier," he said, watching his 4-year-old cousin Leonardo play at a downtown Los Angeles park.

The difference between Sanchez and his brothers' experiences is common, according to a new study of immigrant youth by the Public Policy Institute of California.

The study showed Hispanics who came to the United States as youngsters assimilated quickly and demonstrated academic and English fluency levels similar to native-born Hispanic children. But those who came in their teens face many more problems.

The issue is critical in Arizona after voters essentially outlawed bilingual education - that is, teaching in a student's native tongue - in favor of total immersion programs aimed at making children English-language proficient as soon as possible.

The California study indicated that of those who immigrated before age 10, 33 percent had attended college, compared to 41 percent of native-born Hispanic youths. Of those who arrived later, only 13 percent had attended college.

"We are doing something right because kids who come under the age of 10 are doing almost as well as their native-born counterparts," said the study's author Laura Hill. "They're in school, and that seems to be associated with good outcomes."

But she said more needs to be done to reach those who come later, many of whom are among the more than 70,000 immigrant teens who do not attend high school.

Hill suggested that more educational and health care resources go toward reaching young adults through programs at the workplace or through schools attended by their children. Nearly half of Hispanic women ages 19 to 24 who immigrated to this country in their teens already live with their own children.

The study looked at U.S. Department of Labor data on immigrants ages 13 to 24, focusing on Hispanics who make up the majority of this group.

The study also showed that Asians and white immigrants did better overall than Hispanic immigrants and did relatively well regardless of the age when they came to the United States. The discrepancies between ethnicities continued through second and third generations.

Sanchez, who lived for years with his grandparents in Mexico City after his parents came to the United States, said he stopped attending school in Mexico and it was hard for him to return.

He was finally persuaded to go only after a brother took him to a construction site and pointed out where he was likely to end up if he didn't get to class.