The majority of youngsters with autism who have severe language delay do eventually learn to talk, researchers say.

Some 70 percent of children with the developmental disorder who were not making meaningful phrases by age 4 ultimately achieved some form of speech by age 8 — whether talking in phrases or fluently — according to findings reported Monday in the journal Pediatrics.

The study is based on a review of clinical data on 535 children with autism who had no significant speech by the time they turned 4.

Children were most likely to gain language abilities if they had high nonverbal intelligence and good social engagement, the study found. In fact, researchers said that kids with typical intelligence levels gained language almost six months sooner than those with below average IQ scores.

“We hope the results of this study empower parents of children with autism and severe language delays to know that, with the appropriate therapy, a child will likely make significant gains in this area over time,” said Ericka Wodka, a neuropsychologist at the Kennedy Krieger Center for Autism and Related Disorders, who led the study.

“However, progress should be expected to be slower for those children with lower intellectual abilities,” she said.