As mentioned in subsections 5.2.2 and 5.3.2 above, there is another approach for the explanation of children’s weak syllable omissions besides the Theory of Metrical Phonology. This approach is based on Optimality Theory (see Prince and Smolensky, 1993) and is used for example by Demuth (1995, 1996). Demuth (1995) puts forward several constraints that are ranked in different ways in each developmental stage yielding different output forms (compare her example of Dutch olifant “elephant”, illustrated in Subsection 5.2.2). Among these prosodic constraints are the following (taken from Demuth, 1995 as well as McCarthy and Prince, 1995):
FTBIN: feet are binary
FILL: syllable positions are filled with segmental material
*COMPLEX: consonant clusters are not allowed NO-CODA: syllables may not have codas
PARSE-SEG: underlying segments are parsed into syllable structure
ALIGNPrWd: each lexical stem consists of a prosodic word which consist of a binary branching foot
MAX-IO: every segment of the input has a correspondent in the output (phono-logical deletion is prohibited)
DEP-IO: every segment of the output has a correspondent in the input (phono-logical epenthesis is prohibited)
Some of these prosodic constraints contradict each other which requires a hi-erarchical ordering of these constraints. Constraints that are ranked high are less often violated in contrast to others that are ranked low and may be violated more often. In the adult realization of words such as GermanBall [bal] “ball”, for example,
“MAX-IO” is ranked higher than “NO-CODA”. At an early stage in child language development, the order is reversed which results in output forms such as [ba]. The order of the above mentioned prosodic constraints will play a role for an OT analy-sis of the speech data collected in the production study (Chapter 6). The different hierarchical orders of the children in the different age and language groups will be readdressed in the general discussion (Chapter 8).
The morphological constraint “REALIZE-MORPHEME” prescribes that for every morpheme in the input, some phonological element should be present in the output (e.g., van Oostendorp, 2005). This constraint is violated (along with the “MAX -IO”-constraint), for example, if children omit unstressed definite articles in lapse phrases as found by Gerken (1994b, 1996) and others. In case only parts of the unstressed morpheme are realized, the “REALIZE-MORPHEME”-constraint is not violated but the “MAX-IO” still is. A possible developmental path in the production of lapse phrases could consist of the following stages:
Stage 1: lapse phrases are avoided by the omission of an entire syllable
(“ALIGNPrWd” >> “REALIZE-MORPHEME”, “MAX-IO”)
Stage 2: the first or second weak syllable of the lapse is not yet realized completely whereas the other syllable is realized correctly (“REALIZE-MORPHEME” >> “ALIGNPrWd”, “MAX-IO”) Stage 3: lapse phrases are realized correctly
(“REALIZE-MORPHEME”, “MAX-IO” >> “ALIGNPrWd”)
The extent to which the prosodic and morphological constraints interact in the speech data collected from German and German-Italian children will be shown in the general discussion. In addition, an analysis of the speech data based on the Theory of Metrical Phonology is provided. The following chapter presents the experimental setup and the results of the production study with German and German-Italian chil-dren.
Previous research presented in this chapter demonstrated that there is an inter-relationship between the development of morphological elements and the development of prosodic structures in early childhood. At an early stage, bound morphological items are realized if the syllable structure does not become complex or if the foot does not consist of more than two syllables. In a similar vein, the realization of unbound morphemes depends on the rhythmic structure of the phrase. Only in a later stage when children have acquired more complex prosodic structures are mor-phemes realized correctly. Two theories may be used as a reference to explain these findings: Metrical Theory and Optimality Theory. According to the former theory, young children have a metrical template that prevents output forms that contain complex structures such as consonant clusters and feet consisting of more than two syllables. At a later stage, the template allows more complex structures and children are able to produce adult-like output forms. The latter theory ascribes the reduced output forms in children’s early stages to high ranked constraints that disallow com-plex structures. Later in language development, those constraints are ranked lower than the faithfulness constraints generating correct realizations of morphemes. The two theories are thus not contradictory but explain the findings from two different viewpoints.
Production Study on German and German-Italian Children’s
Development of Complex Structures
Rhyme and meter affect children’s early speech utterances both on the word level and on the sentence level. With respect to single word productions, Grijzenhout and Penke (2005) showed that children’s realization of bound grammatical morphemes depends on the syllable structure that children assume at a certain point in their lan-guage development. The children who participated in Grijzenhout and Penke’s study, produced the German verbal inflection morpheme -t to a greater extent if the rhyme of the verbal stem consisted of two positions only (for more details, see Subsection 5.3.2). Considering sentence productions, children’s early realizations of unstressed morphemes such as articles and prefixes often depend on rhythmic structures (such as an alternating pattern of strong and weak syllables) that children have established at a certain point in their development. Gerken (1994a, 1994b, 1996) as well as Demuth and McCullough (2009) among others (cf. Section 5.2.2) demonstrated that English children are more likely to realize weak syllables if they form part of a trochaic foot.
English articles carry less functional load compared to German articles which inflect for gender, number and case. English and German both possess word-initial weak
syllables but German also has a weak inflectional prefix. Considering different types of German weak syllables, German speech data form an interesting basis for a com-parison with previous findings on English.
So far, only a few studies exist on the prosodically constrained acquisition of morphemes in children with two competing lexicons (see for example Lle´o, 2006 on Spanish speech data by Spanish-German bilinguals and other studies cited in Subsec-tion 5.2.2). The present study contributes to the closure of this gap by investigating the interplay of prosody and morphology in German and Italian. These two languages share a number of properties but are also divergent in a few aspects. German and Italian are both trochaic but German is referred to as a stress-timed language and Italian as a syllable-timed language. The concomitant distinction that is relevant for this study is the lack of vowel reductions in syllable-timed languages. In addition, German and Italian both exhibit verb inflections but the morphological complexity varies for the two languages. German has seven verbal endings to express person, number, tense and mood, one prefix to express past participle and stem vowel alter-nations in strong verbs triggered by certain verbal endings. In comparison, Italian has 25 verbal endings (Schwarze, 1988: 103ff) but neither verbal prefixes nor stem vowel alternations (with the exception of one Italian dialect, see Subsection 3.3.1 above).
Definite articles exist in German and Italian but their morphological complexity dif-fers. In German, four cases, three genders and number are distinguished whereas in Italian, definite articles inflect according to two genders and number. Overall, article use is more frequent in Italian than in German (see Subsection 3.2.1 above).
As mentioned in Subsection 5.3.2, Italian-speaking children correctly apply verb inflections by the end of their second year of life (Hyams 1984, 2008). In this respect, English-speaking children who acquire a sparser inflectional system lag approximately one year behind (Brown, 1973). This difference adds another variable for consider-ation for the present production study. An earlier version of this study including preliminary results was submitted as an article for conference proceedings together with Sascha Gaglia and Janet Grijzenhout. This chapter is more detailed and it presents the final results based only on the data collection of the author of this the-sis. This study focuses on German speech utterances by German and German-Italian
children. For a comparison with Italian speech data, please consult Gwinner, Gaglia and Grijzenhout (2012).
6.1 Research questions
The theoretical background provided in chapters 2 to 4 gives rise to the following research questions:
1. Is the realization of weak syllables in German child speech also conditioned by prosody as in English child speech? Are the realizations of (i) articles, (ii) word-initial weak syllables and (iii) prefixes conditioned by prosody in the same way in German child speech as in English child speech? Do other factors such as grammatical load carried by the respective weak syllables also play a role?
2. When two languages are acquired simultaneously, do they influence each other with respect to the acquisition of phonology and morphology? Are language-specific structures transferred to another language in bilingual children?
3. At what age are German and German-Italian children able to correctly pro-duce all weak syllables in non-trochaic syllable sequences? Which strategies do German and German-Italian children use in order to avoid two adjacent weak syllables? Is the developmental path the same for monolingual children and bilingual children who acquire two languages simultaneously with different prosodic and morphological properties?