HOLYOKE — Within the walls of a small classroom papered with posters of the alphabet, rudimentary English words and a sombrero, students Elizabeth Enriquez and Esther Figueroa wrestle with intricacies of the language at the same desk, but at different ends of the immigrant timeline. Figueroa, 54, has spent the past 18 years since her arrival from Mexico rearing four children while her husband works at a nearby farm.