Alphabetic orthographies vary in terms of depth, i.e., in terms of the complexity and consistency of the phoneme-grapheme correspondences (Seymour, 2008). Therefore, they can be classified in a depth continuum, where transparent orthographies (e.g., Finnish) are those that have mainly consistent correspondences between phonemes and graphemes, whereas opaque orthographies (e.g., English) have more complex and inconsistent correspondences. Intermediate depth orthographies, such as European Portuguese, are in the middle of the continuum, being composed of some regularities and some more complex relationships between sounds and letters (Seymour et al., 2003;Sucena et al., 2009). Oral reading fluency (ORF) can be defined as "the ability to read a text quickly, accurately, and with proper expression" (National Institute of Child Health and Human Development, 2000, p. 3-5). Evidence for a close relationship between ORF and reading comprehension has been systematically provided, not only in opaque (