The unique contribution of vocabulary in the reading development of English as a foreign language

The opaque English orthography complicates learning to read, as irregular words, such as the word pint, cannot be Addread accurately by decoding. Studies with first language (L1) English children show that vocabulary facilitates word reading, especially in the case of irregular words. It is unclear whether this influence of vocabulary extends to children learning to read English as a foreign language (EFL). When learning EFL, words are often encountered in print first, potentially making orthographic knowledge especially important. Orthographic knowledge might partially account for the effect of vocabulary on irregular word reading. In this study, 455 Dutch students in their first year of formal English education (11–13 years, Grade 7) were followed. Their English vocabulary, orthographic knowledge, and irregular, regular and pseudoword reading skills were assessed in fall and spring. Commonality analyses showed that vocabulary contributed more to irregular than to regular or pseudoword reading, even when controlling for orthographic knowledge. Additionally, orthographic knowledge was related to irregular word reading concurrently, independent of vocabulary. Longitudinal analyses showed that vocabulary and orthographic knowledge also had independent effects on the development of irregular word reading, but not on regular or pseudoword reading. Overall, the predictors for EFL word reading were in line with previous L1 findings. Both EFL and L1 learners use vocabulary and orthographic knowledge to read irregular words. This suggests that the relationship between vocabulary and word reading is related to aspects of the English orthography itself. To enable EFL learners to read irregular words, it is important to teach the other constituents of word knowledge, that is, vocabulary and orthography