Principles and parameters in second language acquisition

3.5.3.1 The head-parameter

Let us return to the first examples that we used to illustrate first language acquisition, namely the structure dependency principle and the head para-meter.

First, there seems to be no evidence in second language grammars that learners ever violate the structure dependency principle. From the very onset of second language development, learners seem to know that the sec-ond language will be hierarchically structured in terms of phrases, rather than linearly ordered.

Second, we saw that there are two possible settings for the head param-eter, head-first and head-last. Both French and English are head-first languages, that is, the head precedes its complements. However, in French, although all phrases normally exhibit this order, there is one instance when this order changes (Towell and Hawkins, 1994, p. 68; Hawkins, 2001, pp. 11-12). This is in the case of unstressed object pronouns, as exemplified below:

1. Le chat [^mange [NP/a souris]] (the cat eats the mouse) 2. Le chat [vp[Np^] mange] (the cat it eats = 'the cat eats it')

In Verb-Phrases in French where the complement is a full Noun-Phrase (1), the head verb precedes its complement as normal; however, when the com-plement is an unstressed pronoun (2), the head verb follows it. Note that in English, the head direction is the same whether the complement is a full N P or a pronoun.* From an acquisitional point of view, we have seen that chil-dren need minimal evidence in order to set the head-direction parameter, as all phrases in a giverf language normally follow the same order. For French children, there is ample evidence in the language around them that French is head-first. We would therefore expect French children to set the parameter early on (and we saw in Section 3.4 that children do this, as early as the two-word stage), and to always place the head before its complement.

This is in fact the case, and children produce utterances such as *Le chat mange la> before going through a stage of omitting the pronoun altogether

*Le chat mange 0 , and later still inserting it in its target position Le chat la mange. (Clark, 1985; Hamann et al.> 1996).

If this developmental sequence is indeed because French children have set the head-parameter and have thereafter to accommodate this particular structure, which seems to go against it, then we should expect the same to happen for second language learners of French, as the task facing them is exactly the same. If Universal Grammar is available to them, they would also find ample evidence in French for setting the head-direction param-eter.

In fact, the stages of development that LI English speakers go through in acquiring this pattern in L2 French are very similar to the stages that child LI learners of French go through in acquiring it. Following an initial stage where learners leave object pronouns post verbally in the position occupied by full noun phrases, e.g. Le Men a mange les, 'The dog has eaten them' (Zobl 1980;

Clark 1985), they go to a stage of omission of the pronoun: Le chien a mange 0 (Adiv 1984; Schlyter 1986; Veronique 1986) before eventually acquiring preverbal object pronouns: Le chien les a manges.

(Towell and Hawkins, 1994, p. 69) It is interesting to note that French learners of English as a second language do not have problems in acquiring object pronouns in English, and do not

*In fact, this is not a violation of this parameter setting, but it occurs because unstressed pro-nouns in French cliticize on to the verb (i.e. attach themselves to the verb). In other words, object pronouns originate after the verb as expected given that French is head-first, and sub-sequendy move to a pre-verbal position.

go through a stage of preposing the pronoun (*the cat it eats) nor through a stage of omitting the pronoun (Zobl, 1980). This is to be expected if we assume that, on the basis of ample evidence in English that it is head-first, second language learners set the head direction parameter early on and apply it consistently.

It is important to note at this stage that, because both French and English are head-first languages, we cannot say whether these observations are due to the fact that second language learners reset the parameter to its correct value, or simply transfer their first language parameter value. What is inter-esting, however, is that Frencn learners do not transfer the idiosyncratic property of French for pronoun placement.

In order to know whether the head-parameter can be reset, it is necessary to investigate the acquisition of, say, a head-first language by learners whose first language is head-last. Flynn (1983,1984,1987) studied the role of this parameter in Japanese learners of English. (We have already seen that Japanese is a head-last language.) She concludes 'that, from the earliest stages of acquisition, Japanese speakers learning English as a Second Language (ESL), are able to acquire the English value of the head-direction parameter' (Flynn, 1996, p. 135).

The evidence presented here therefore seems to suggest that, in the case of the head-parameter at least, second language learners have access to Universal Grammar in the same way as children do. We have to be careful, however, not to draw hasty conclusions on the basis of evidence relating to one structure only, and we have to bear in mind that other explanations that do not involve Universal Grammar might be possible, and have indeed been put forward.

3.5.3.2 Strong or weak Infl

We have discussed earlier that functional categories are now thought to be the primary location for parametric variation (although headedness is an exception as it applies to both lexical and functional categories), and we used the example of the strength of Infl in French and English, respectively.

Remember that in French, Infl is strong and forces the verb to rise past, for example, adverbs, negators, etc., unlike in English where Infl is weak and the verb remains within the verb-phrase. French learners of English there-fore have to reset the Infl parameter to [-strong], and English learners of French have to reset it to [+strong]. Several studies have investigated this property (seeWhite, 2003, for a review).Yuan (2001) studied the acquisition of Chinese (weak I) by French (strong I) and English (weak I) learners. He found that all learners, regardless of their first language or their proficiency

level, realized the ungrammaticality of verb-raising in Chinese, suggesting that they were able to reset this parameter. Another study by White (1992), however, found somewhat different results. She studied the acquisition of verb-raising in questions, negatives and adverb placement, in French learn-ers of English as a second language. Her learnlearn-ers (beginnlearn-ers) seemed to have realized that English has weak I in the context of questions and negatives, but not in the context of adverbs. Learners rejected sentences such as:

Like you pepperoni pizza?

The boys like not the gi^ls

with a high degree of accuracy, but not:

Linda takes always the metro

which they accepted to a considerable extent.

White argues this might be because we are dealing with two different parameters underlying these properties. For further details, see White (2003, pp. 129-32). The results to date on this particular parameter are somewhat inconclusive. The Universal Grammar framework, however, enables researchers to develop clear hypotheses of this type about second language acquisition issues.

3.5.3.3 Current debates and hypotheses about parameter resetting As we have seen, one of the recent developments in the context of the Minimalist Program has been the importance given to functional categories as the location of parametric variation. In first language acquisition research, this has given rise to intense debates about whether children in the early stages only have access to lexical categories and lack functional cat-egories, which would explain the telegraphic nature of their early utterances (i.e. the fact that children's early utterances contain content words exclu-sively, and no function words, e.g. daddy go; mummy hat). More specifically, the debate centres on whether functional categories are available from the start but are not in evidence because of external factors (e.g. for pragmatic reasons: the Continuity hypothesis (Weissenborn, 1992; Penner and Weissenborn, 1996); whether they mature over time, that is, come 'on line' at specific ages: the Maturation hypothesis (Haegeman, 1996; Harris and Wexler, 1996); or whether children 'build⁵ their grammar gradually as they learn the lexicon of their language and project the relevant structure: the 'structure-building' approach (Radford, 1990, 1996). For a discussion of these issues, see Atkinson (1996).

Similar debates about what is termed the Initial State (the subcon-scious linguistic representations second language learners have at the onset of SLL) are also taking place in second language acquisition. Some researchers have argued that functional categories are also absent in the very early stages of adult second language acquisition (Vainikka and Young-Scholten, 1996a, 1996b, 1998; Hawkins, 2001; White, 2003;

Myles, in press a), this phenomenon manifesting itself by a lack of mor-phological markings and of syntactic movement. Other researchers, how-ever, have argued that functional categories are indeed present in the early stages in child second language (Lakshmanan, 1993; Lakshmanan and Selinker, 1994; Grondin and White, 1996) and also in adult second language (Schwartz and Eubank, 1996; Schwartz and Sprouse, 1996;

Schwartz, 1998), and that the lack of morphological markings is not a syntactic issue. Some recent accounts argue for a structure-building approach to second language development (Herschensohn, 2000;

Hawkins, 2001).The debate is likely to go on for some time, complicated by the fact that functional categories themselves are not yet very clearly defined in Universal Grammar theory.

What is becoming increasingly clear within the Universal Grammar framework is that the question which has generated so much research over the last 15 years or so - namely, whether Universal Grammar is available to second language learners or not - is now being replaced by more focused questions about which sub-components of Universal Grammar might be available or not to the second language learner, how Universal Grammar interacts with other modules involved in language learning, and the role played by the first language settings. Principles are generally thought to be available, as second language learners do not seem to produce interlan-guages that violate them, and most of the work has concentrated on testing the availability of parameters, with as yet somewhat inconclusive results.

However, recent book length treatments of the second language acquisition of syntax within this framework reflect considerable advances in attempts to understand the role of Universal Grammar within second language acqui-sition (Herschensohn, 2000; Hawkins, 2001; White, 2003).

In a review, White suggests:

that L2 learners often develop IL [interlanguage] grammars that are different from the grammars of NSs [native speakers] but that are nevertheless con-strained by UG, and that this is due, in part, to properties of the L2 input interacting with UG and the LI grammar. Many questions remain to be answered, including the question of why some learners 'fossilize' with these divergent IL grammars, whereas others successfully attain a nativelike gram-mar; why some parameters are successfully reset, whereas others are not, why

positive L2 input is only sometimes successful as a trigger for grammar change.

(White, 1996, p. 115)