This study modeled vocabulary trajectories in 91 English language learners (ELLs) with Punjabi, Tamil, or Portuguese home languages, and 50 English monolinguals (EL1) from Grades 1 to 6. The concurrent and longitudinal relationships between phonological awareness and phonological short-term memory and vocabulary were examined. ELLs underperformed EL1s on vocabulary across all grades. Although vocabulary grew faster in ELLs than in EL1s in the primary grades, they did not close the gap after 6 years of English schooling. Mutual facilitation was found between phonological awareness, English-like nonwords, and vocabulary. A unidirectional relationship was found between Hebrew-like nonwords and vocabulary suggesting that the relationship between phonological short-term memory and vocabulary can be more accurately captured when using nonwords based on a remote, unfamiliar language.