It has been forcefully argued that reading comprehension cannot succeed unless the reader appreciates morphological word formation, that is, how differences in word forms relate to differences in meaning (Carlisle, 2003). This suggests that an explicit understanding of morphological relations, termed morphological awareness, is a prerequisite to skilled reading. In fact morphological awareness is related not only to reading comprehension, but also to spelling (e.g., Deacon et al., 2009; Casalis et al., 2011), vocabulary (McBride-Chang et al., 2005; Sparks and Deacon, 2015), and word and pseudoword reading (Deacon and Kirby, 2004; Kirby et al., 2012). The contribution of morphological awareness to spelling is robust to a multitude of control variables (Deacon et al., 2009) and includes both inflected and derived forms (Deacon et al., 2010) beyond the spelling of specific morphemes (Casalis et al., 2011).

Deacon and Kirby (2004) examined the role of both phonological and morphological awareness in learning to read for English-speaking Canadian children. They investigated the longitudinal prediction of Grades 3, 4, and 5 pseudoword reading, single word reading, and reading comprehension from Grade 2 phonological and morphological awareness. They found that morphological awareness made a small but unique contribution to all aspects of reading development – mainly pseudoword reading and reading comprehension – during the 3 years of middle elementary school, over and beyond the effect of phonological awareness. They argued that morphological awareness might have accounted for more variance in the reading variables if multiple measures of various formats and tapping a broader range of derivations and inflections had been used. The present study addressed this methodological limitation by assessing children in an elaborate and systematic battery of phonological and morphological awareness tasks.

In another study of English-speaking Canadian children, Deacon et al. (2009) examined the predictive value of morphological awareness, assessed in the early school years, for the prediction of spelling, assessed in middle elementary grades. They reported that Grade 2 morphological awareness accounted for approximately 8% of the variance in Grade 4 general spelling skills, beyond the effect of verbal and non-verbal intelligence, phonological awareness, verbal short-term memory, and rapid-automatized naming (RAN).

Few studies have studied the contribution of morphological awareness assessed before the onset of formal reading instruction. Casalis and Louis-Alexandre (2000) studied the longitudinal contribution of phonological and morphological awareness to decoding and reading comprehension. They assessed French-speaking kindergarten children in a variety of morphological awareness tasks measuring both inflectional and derivational morphology. Their findings showed strong correlations between phonological and morphological awareness tasks, as well as unique contributions of both skills to Grade 2 decoding skills and reading comprehension. However, they only analyzed the correlations for individual tasks and did not examine the overall effects of morphological and phonological awareness skills by considering all the corresponding tasks together. Therefore, the total magnitude of the longitudinal relationship remained unknown.

More recently, using latent variable modeling in Chinese, Pan et al. (2016) found that pre-literate syllable and morphological awareness predicted character reading, reading fluency, reading comprehension, and writing at the age of 11 years, beyond any effects of phonological awareness, but only indirectly, that is, through post-literate morphological awareness assessed at the ages of 7–10 years.

The longitudinal relation between early morphological awareness and reading and spelling skills has also been studied in Greek. Manolitsis (2006) found that morphological awareness, assessed in kindergarten, longitudinally predicted Grade 1 word reading but its contribution to accuracy was not significant when kindergarten phonological awareness was controlled for. Pittas and Nunes (2014) assessed first and third graders in three morphological awareness tasks: a pseudoword inflection task, a sentence analogy task, and a morphological relatedness task. They found a unique contribution of morphological awareness to reading – but not to spelling – assessed 8 months later, even after partialling out the effects of grade, verbal ability, phonological awareness, and initial reading level.

Grigorakis and Manolitsis (2016) examined the longitudinal prediction of Greek morphological spelling from morphological awareness measured before and at the beginning of formal literacy instruction. They assessed 229 kindergarten children 5–6 years old on a variety of morphological awareness tasks measuring their ability to recognize and manipulate inflections, derivations, and compound words. Spelling of inflectional suffixes in words and pseudowords was assessed at Grades 1 and 2. Morphological awareness was a significant longitudinal predictor of word spelling, surviving control for verbal and non-verbal intelligence, verbal short-term memory, receptive and expressive vocabulary, letter sound knowledge, RAN, and phonological awareness.

Finally, in a cross-linguistic study comparing English, French, and Greek, Desrochers et al. (2017) found that Greek children’s morphological awareness skills at the beginning of Grade 2 were unique predictors of reading comprehension and spelling, but not of reading accuracy – as in English – and fluency – as in both English and French – at the end of the same grade.

Evidence for the importance of morphological awareness has also been provided by intervention studies. If morphological awareness forms a critical substrate for reading development, then training in morphological awareness, if successful, should lead to measurable improvements in reading performance. Due to their experimental – rather than correlational – nature, studies of morphological awareness training constitute an empirically crucial source of evidence regarding the connection between morphological awareness and literacy. Indeed, instruction in morphological awareness has been shown to result in benefits across literacy domains, especially when combined with phonological awareness training (e.g., Lyster, 2002; Lyster et al., 2016; Manolitsis, 2017; see meta-analyses and systematic reviews in Reed, 2008; Bowers et al., 2010; Carlisle, 2010; Goodwin and Ahn, 2010, 2013).

However, even though dozens of morphological awareness studies have accumulated to date, as seen in the aforementioned reviews, a confident conclusion remains unwarranted because it has been challenging to establish the specificity of training. The majority of studies have failed to employ an active control group receiving instruction of similar structure and intensity but non-morphological in content. Indeed, many studies have simply compared the experimental group to a passive control group not receiving any special instruction but following the regular classroom program. When active control groups are employed the benefits to literacy from morphological training are not significantly stronger (e.g., comparing against phonological awareness training; Lyster, 2002; Lyster et al., 2016).

An additional difficulty with the theoretical interpretation of the majority of these training studies is that they have relied, at least in part, on printed materials or strategies potentially exploiting the orthographic knowledge of participants, thereby obscuring the origin of the observed effects. That is, although the focus of the instruction was on the morphological aspects of words, if training took place using written words then children may have exhibited literacy gains due to the fact that they received a form of reading or spelling instruction rather than to morphological awareness per se.

In sum, despite the recent surge in interest in the relationship between morphological awareness and reading skill development, and the strong evidence for its importance, the relevant literature has not conclusively established the precedence, or necessity, of morphological awareness for reading development and for particular reading skills. Many studies have examined concurrent correlations and most have assessed children in elementary grades, for which reciprocal effects may have contributed to the reported findings. That is, if morphological awareness is assessed after the onset of reading instruction, it is possible that exposure to the various printed word types may have contributed to the further development of morphological awareness. Therefore, a finding of robust correlations may conceivably be due to an inverse direction of causation than typically hypothesized.

Although longitudinal studies are one step toward addressing this shortcoming, it is also critical that the first assessment of morphological awareness takes place before the onset of reading instruction, to minimize effects of exposure to print. This requires the development and validation of appropriate testing materials for preschoolers that arguably address metalinguistic morphological skills. In the present study we have thus examined the longitudinal prediction of early (Grade 1) reading skills by preschool morphological awareness, controlling for phonological awareness and vocabulary. To obtain a more nearly complete picture of the importance of morphological awareness for reading skill development, we have applied a comprehensive battery of reading outcomes, including word and pseudoword accuracy, reading fluency, reading comprehension, as well as spelling.

Typical language development involves unconscious use of morphology. Very young children produce overgeneralizations, such as “buyed” (instead of “bought”). The production of these errors suggests a gradual development in understanding the rules of inflectional morphology (Berko, 1958; Selby, 1972). Nonetheless, the boundary between tacit knowledge of morphological processes and conscious morphological awareness has not been sufficiently investigated. In many cases it is not clear whether differences in measures of morphological awareness reflect differences in metalinguistic awareness or in implicit morphological knowledge (Nagy et al., 2014). Metalinguistic awareness is thought to be a special kind of linguistic functioning, beyond language acquisition, which develops in middle childhood (Tunmer et al., 1984).

The morphological processes of grammatical inflection and productive derivation seem to follow a similar but non-simultaneous developmental progression. Evidence shows that awareness of inflectional morphology is acquired in the first school years (Diakogiorgi et al., 2005; Kuo and Anderson, 2006), whereas awareness of derivational morphology develops toward the fourth year (Anglin, 1993; Carlisle, 2000), and continues to grow throughout the school years (Berko, 1958; Anglin, 1993; Berninger et al., 2010). Carlisle (1995) suggested that children’s awareness of derivational morphology makes a transition from an implicit to an explicit level at the ages of kindergarten and first grade.

Morphological awareness tasks have been classified according to their cognitive and meta-cognitive requirements, which may operate at either an implicit or an explicit level (Deacon et al., 2008). Lexical judgment tasks, which require children to decide whether two words are related or not, have been widely used to assess implicit morphological skills (e.g., Mahony et al., 2000; Duncan et al., 2009), whereas analogy and production tasks have been used to tap explicit skills (e.g., Berko, 1958; Derwing, 1976; Nunes et al., 1997; Carlisle, 2000; Kirby et al., 2012). Production tasks have also been differentiated between implicit and explicit (Casalis and Louis-Alexandre, 2000).

Diamanti et al. (in press) recently examined the development of morphological awareness in Greek children 4–7 years old. They compared the domains of inflectional and derivational morphology, adopting a distinction between two levels, namely epilinguistic control and metalinguistic awareness. Epilinguistic control refers to an intermediate level of elementary awareness that has been posited to intervene developmentally between the acquisition of the linguistic skill and the acquisition of metalinguistic awareness (Gombert, 1992). In contrast, metalinguistic awareness refers to the individual’s ability to reflect upon and consciously manipulate morphemes, as well as the ability to deliberately apply word formation rules. Following Carlisle (1995), epilinguistic control is evidenced in judgment tasks, whereas full-blown metalinguistic awareness is evidenced in production tasks (see Diamanti et al., in press, for further discussion). In addition to the expected performance increase with age, Diamanti et al. (in press) found that a single factor sufficed and accounted for 0.59 of the variance in the four tasks, consistent with a common developmental path underlying both domains and both levels of morphological awareness. In comparison of the developmental growth curves among tasks, they found that production of derivational morphemes was more difficult than production of inflectional morphemes and judgment of derivational morphemes, whereas the differences between the two inflectional tasks and between the two judgment tasks were not significant.

Given these findings, Diamanti et al. (in press) suggested that at these ages epilinguistic control is similarly effective for the two morphological domains whereas full metalinguistic awareness of derivational morphology trails behind that of inflectional morphology, at least as measured by these specific tasks. Thus, on the one hand, this study highlighted the need for early tracking and distinctions among levels and domains of morphological awareness. On the other hand, it demonstrated the reliability and validity of the materials used and the potential of this combination of subscales to form a reliable and coherent scale for overall wide-range assessment of morphological awareness in the preschool and early elementary school age range. The present study is a follow-up of a subset of the children in that study, who attended preschool at the time and were assessed again 1 year later, in Grade 1, on reading-related outcome variables.

This subsection is reproduced from Diamanti et al. (in press). Greek is a language with rich inflectional and derivational morphology (see Ralli, 2003) and relatively consistent orthography (Protopapas and Vlahou, 2009). Nouns and adjectives are obligatorily inflected for gender, number, and case via fusional suffixation. For example, the noun χoρóς (/xoros/ “dance”) is composed of the stem χoρ – (/xor/ expressing the core semantics) and the inflectional suffix – oς (/os/ signifying masculine singular nominative case). Verb forms also include a stem and an obligatory inflectional ending, both of which may be simple or complex. Verbs are inflected for voice, aspect, tense, number, and person [Ralli, 2003; see Klairis and Babiniotis (2004) and Holton et al. (2012) for comprehensive descriptions]. For example, the verb χoρ𝜀ύω (/xorevo/ “I dance”) is composed of the same stem χoρ – (/xor/), the derivational affix – 𝜀ύ – (/ev/ forming a verb from a noun), and the inflectional suffix – ω (/o/ signifying first person singular).

Distinct inflectional classes are recognized for both nouns/adjectives and verbs, each with its own set of suffixation and stem alternation rules (Ralli, 2003, 2005; Holton et al., 2012). Word formation in Greek also includes systematic derivational processes, especially for nouns (based on verb stems) and adjectives (based on verb and noun stems). Compounding is also highly productive, as new adjectives, nouns, and verbs can be created from existing stems and words [see Ralli (2003, 2005) for more information].

Morphology has extensive orthographic consequences in Greek, insofar as derivational and grammatical suffixes are associated with specific spellings, which also serve to disambiguate homonyms. Knowledge of the inflectional type is often required for correct spelling of adjective, noun, and verb suffixes [see Protopapas (2017) for more information and references]. Therefore, it seems reasonable to hypothesize that an understanding of morphological processes will be especially beneficial in learning to spell, and particularly useful in spelling the inflectional suffixes (Grigorakis and Manolitsis, 2016). This is important in light of the fact that Greek morphological spelling is known to be challenging, including both inflectional and – especially – derivational suffixes (Protopapas et al., 2013a; Diamanti et al., 2014).

A small amount of instructional activity related to morphological awareness takes place informally in the Kindergarten curriculum as part of vocabulary instruction, in the context of shared book reading and retelling, including discussion about word types such as diminutive derivation and number inflection, along with phonological awareness activities such as letter–sound association and identification. Systematic decoding is taught in Grade 1, so that most children are able to read by mid-grade, after which point some instruction related to morphological awareness appears, for example teaching the distinct spellings of noun and verb vowel endings (i.e., inflectional suffixes).

Most Greek children have mastered the inflectional paradigms of the language to a large extent by the age of entering elementary education, at least as far as the suffixes with orthographic consequences are concerned (i.e., case, gender, and number, for adjectives and nouns, and person and number, for verbs). Normally developing kindergarten children approach ceiling performance in the production of verb past tense and noun gender, number, and case (Mastropavlou, 2006) although persistent difficulties with verb aspectual formation and noun gender are observed in certain word classes with unusual properties (Stavrakaki and Clahsen, 2009; Varlokosta and Nerantzini, 2013, 2015). Thus, morphological acquisition is largely but not entirely completed by Grade 1.

The study sample consisted of 104 children (54 girls and 50 boys) assessed at the middle of kindergarten (February–March; age M = 67.3 months; SD = 3.6) and again at the end of Grade 1 (April–May; about 14 months later). They were native speakers of Greek and did not have any diagnosed developmental delay or emotional disorder prohibiting them from enrollment in typical (general) education settings. They were recruited from schools in rural (17%), semi-urban (19%), and urban (63%) areas of four geographically dispersed provinces of Greece, including a variety of socioeconomic and ethnic backgrounds. Sample demographics represent a close approximation to the Greek population (77% urban and 23% rural) based on the 2011 census.

Permission to conduct the study in these public schools was granted by the Ministry of Education following formal review and approval of the study plan by the Research Office of the Educational Policy Institute. Parental and school approval, as well as the child’s oral assent, were obtained prior to test administration. Participants were not specifically selected; rather, consent forms were distributed to entire classrooms and children who returned the signed parental consent were included in the study.

Time 1 (predictor) measures included receptive and expressive vocabulary, and phonological and morphological awareness. These tasks were administered through an Android application (app) for mobile devices (tablets) featuring automatic application of ceiling rules. Time 2 (outcome) measures included word and pseudoword reading accuracy, text reading fluency and comprehension, and spelling. The four reading outcome measures were from “ΔAΔA,” a standardized reading test by Padeliadu et al. (in press).

All measures were administered individually by specially trained research assistants, following a common procedure, in a quiet room at the children’s kindergarten (Time 1) or school (Time 2). Time 1 (predictor) measures were administered in two to three sessions of 40–45 min within 2 weeks (in the context of a variety of other tasks not reported here) using a tablet app custom made for this purpose. All visual and auditory stimuli were provided by the app as images and pre-recorded utterances. Scoring was automated when possible (i.e., evaluation of selection accuracy), or entered manually after administration when human judgment was necessary (i.e., evaluation of spoken responses). Time 2 (outcome) measures were administered individually in one 40–45-min-long session in the traditional (paper and pencil) format.