Any description of what it means to know a word in a foreign language is likely to include recognition of form, both how a word sounds when heard and what it looks like when written. However, tests of vocabulary knowledge focus almost exclusively on the written form of the word. We have little idea of learners' phonological vocabulary knowledge or how it might interact with orthographic knowledge. It is suspected that written vocabulary tests may underestimate the vocabulary knowledge of native Arabic speakers, who often handle English orthography poorly. This paper reports a comparison of the phonological and orthographic vocabulary sizes of Greek and Arabic native speakers. Results suggest that written tests do not underestimate Arabic speakers' vocabulary size. The two aspects of vocabulary knowledge develop differently with language level. Very proficient learners of EFL are characterized by an orthographic word recognition much greater than their phonological word recognition.