What phonological process often persists beyond the age of 3?

The correct answer is gliding. Gliding is a phonological process where sounds typically produced as liquids (like /l/ and /r/) are replaced with glides (such as /w/ and /j/). This process often persists beyond the age of 3, as some children continue to substitute these sounds into their speech even as they develop further.

In early childhood development, children frequently use various phonological processes as they learn how to articulate sounds. While many processes, such as reduplication, fronting, and final consonant deletion, tend to resolve as children age and improve their speech capabilities, gliding can linger for a longer period. Children may exhibit this pattern well into their preschool years and sometimes even into early elementary school, thus indicating that it is a more persistent phonological process when compared to others listed.