Abstract
<p>Dyslexia is expressed differently across writing systems because languages vary in the phonological and morphological units represented in print and in the consistency of mappings among print, sound, and meaning. These differences are consequential in foreign-language learning: adequate first-language literacy does not ensure that units required by another writing system are equally accessible or efficiently processed. When such difficulties are overlooked or misinterpreted, appropriate support may be delayed, limiting participation in learning and assessment. This review connects cross-linguistic accounts of literacy with a process-based interpretation of phonological assessment. We distinguish structural grain size, the units represented by a writing system, from processable grain size, the units that a learner can reliably access and use under specific task and instructional conditions. We argue that phonological task scores reflect multiple processing demands rather than a single mechanism. This processing-stage framework distinguishes auditory–phonological encoding and task-relevant access, task-directed operation, phonological reconstruction, and response selection or production, while treating temporary maintenance, performance monitoring, phonological rehearsal, and inner speech as cross-stage processes. Finally, we outline a process-informed extension of dynamic assessment that compares theoretically motivated support conditions to generate instructional hypotheses and determine whether learners with similar scores benefit from different forms of support.</p>