Age of Acquisition and Proficiency as Factors in Language Production: Agreement in Bilinguals Rebecca Foote February 21, 2007 Univ. of Illinois at Urbana-Champaign

2 Central question in SLA Why is the outcome of second language (L2) acquisition different from that of first language (L1) acquisition? Specifically, why is success inevitable in L1 acquisition but failure to become nativelike the standard for L2 learners (late bilinguals)?

3 Age effects in language acquisition Critical period hypothesis – Critical / sensitive period for language learning: “a limited developmental period during which it is possible to acquire a language, be it L1 or L2, to normal, nativelike levels” (Birdsong, 1999) But does this apply to all aspects of language acquisition? Are there particular linguistic structures or psycholinguistic processes that are not susceptible to age effects?

4 What is it that’s not nativelike about L2 learners (late bilinguals)? Variability in late bilingual production of agreement morphology: – Example: Jim runs to the store. *Jim run to the store. Two possible sources for the problem: – Deficit in linguistic knowledge (competence) Beck (1998), Eubank, (1994), Hawkins & Chan, (1997), Meisel (1990, 1997), Schachter (1989, 1990) – Psycholinguistic processes of language production (performance) Lardiere (1998a, 1998b), Prévost & White (2000), Fernández (1999)

5 What about early bilinguals? Don’t seem to show same morphological variability as late bilinguals Don’t always pattern with monolinguals – Kohnert, Bates, & Hernández (1999), Montrul (2002) Are they more accurate in language processing and production than late bilinguals? What if they are not of “nativelike” proficiency?

Experimental study: Subject-verb number agreement production in English-Spanish bilinguals

7 Subject-verb number agreement production in Spanish and English Verb number controlled by the number of the subject noun phrase – The cats are black. – Los gatos son negros. – The lamp is beautiful. – La lámpara es bella. But how do we account for subject-verb number agreement errors (The occurrence of these errors are underestimated)? – Agreement potentially influenced by: Grammatical number of the subject noun phrase “Notional” or “conceptual” number of the subject noun phrase Attraction Conceptual number and attraction working together

8 Grammatical vs. conceptual number Grammatical number – Lexically specified number of head noun Conceptual number – Number of referent in the speaker’s mental model – one thing or more than one thing? Singular or plural? – Jeans – Faculty – Family – Clothes – Clothing

9 Attraction *The tree behind the houses ARE large. Error common to native speakers of both Spanish and English – (Bock & Miller, 1991; Vigliocco, Butterworth, & Garrett, 1996)

10 Conceptual number and attraction working together Single referent complex NP: – The bus to the schools… Distributive referent complex NP: – The label on the bottles… Distributivity effects in subject- verb number agreement – The label on the bottles are… vs. – The bus to the schools are…

11 Subject-verb number agreement production in Spanish and English Psycholinguistic research on agreement production – Speech error research – determine which factors play a role Grammatical number only? Conceptual number as well? – Bock & Miller (1991) Sentence-fragment completion methodology – “The label on the bottles…”

12 Cross-linguistic differences in subject- verb number agreement production English: – Grammatical number (no distributivity effects) – Bock & Miller (1991) The label on the bottles are… = The bus to the schools are… Spanish: – Conceptual number as well as grammatical number (distributivity effects) – Vigliocco, Butterworth, & Garrett (1996) The label on the bottles are… > The bus to the schools are…

13 Maximalist model of agreement production (Vigliocco, Butterworth, & Garrett, 1996) Interactive model that assumes a language production system with various levels or steps (Levelt, 1989; 1999) – Message conceptualization – Grammatical encoding – Morphophonological encoding – Phonetic encoding – Articulation Accuracy of agreement production ensured by system’s use of the maximal amount of information available to it; information across levels or steps is shared Accounts for cross-linguistic differences in the influence of conceptual number on agreement production by proposing different mechanisms of agreement for different languages – English: Feature copying – Spanish: Feature unification

14 Maximalist model of agreement production – feature copying (from Vigliocco, Butterworth, & Garrett, 1996, p. 270)

15 Maximalist model of agreement production – feature unification (from Vigliocco, Butterworth, & Garrett, 1996, p. 271)

16 Maximalist model of agreement production – cross-linguistic differences Languages with richer inflectional morphology, flexible word order and the possibility of null subjects are more likely to produce agreement by means of feature unification and therefore to show conceptual effects in agreement production Languages with poorer inflectional morphology, less flexible word order and little possibility of null subjects are more likely to produce agreement by means of feature copying, and therefore to show no conceptual effects in agreement production

17 Agreement production in bilinguals How do cross-linguistic differences play out in bilingual agreement production? – Cause of variability in late bilingual production of agreement morphology? Proficient bilinguals appear to process and produce agreement in the same way in both of their languages – Nicol, Teller, & Greth (2001) – Nicol & Greth (2003)

18 Experimental study Experiment 1 – Agreement production in English and Spanish monolinguals Experiment 2 – Agreement production in English-Spanish bilinguals

Experiment 1: Monolinguals

20 Experiment 1: Research Question Are there differences in the mechanics of subject- verb number agreement production in Mexican Spanish, Dominican Spanish, and English? – Previous research indicates cross-linguistic differences between Spanish and English (Vigliocco, Butterworth, & Garrett, 1996) with respect to the factors that influence singular or plural agreement Grammatical number Conceptual number

21 Experiment 1: Participants English monolinguals (n = 18) Mexican Spanish monolinguals (n = 32) Dominican Spanish monolinguals (n = 28)

22 Experiment 1: Materials Language history questionnaire Experimental task – Modified sentence-fragment completion task

23 Experiment 1: Stimuli Auditory stimuli – 2 sets (1 English, 1 Spanish), 32 complex subject noun phrases – 16 with distributive referents as head nouns The label on the bottles – 16 with single referents as head nouns The bus to the schools – 64 filler subject noun phrases The chairs Pictorial stimuli – Each fragment associated with a line drawing of its referent Example: The stamp on the envelopes

24 Experiment 1: Procedure Participants see a picture in the center of the computer screen, followed by a sentence fragment played over the speakers Repeat and complete fragment as quickly and accurately as possible, naming the color of the head noun’s referent

25 Experiment 1: Example trial

26 Experiment 1: Results Participants’ responses digitally recorded, transcribed, and coded for errors Predictions – If participants are sensitive only to grammatical number, they will make approximately the same number of errors with single and distributive referent fragments. The label on the bottles are… = The bus to the schools are… – If participants are sensitive to conceptual number, they will make more errors with distributive referent fragments than with single referent fragments. The label on the bottles are… > The bus to the schools are…

27 Experiment 1: Results Are participants sensitive only to grammatical number, or to conceptual number also? The label on the bottles are… > The bus to the schools are…

28 Experiment 1: Research Question Are there differences in the mechanics of subject-verb number agreement production in Mexican Spanish, Dominican Spanish, and English? – NO…All three languages/dialects evidence conceptual effects in agreement production

29 Experiment 1: Discussion English, Dominican Spanish, and Mexican Spanish all show sensitivity to conceptual number in agreement production – In terms of the maximalist model (Vigliocco, Butterworth, & Garrett, 1996), all three effect agreement by means of feature unification

Experiment 2: Bilinguals

31 Experiment 2: Research questions Do English-Spanish bilinguals produce subject-verb number agreement in the same manner in both languages? What role do age of acquisition and proficiency play in bilingual agreement production? – Manner – Accuracy

32 Experiment 2: Participants Early English-Spanish bilinguals (age of acquisition of both languages < 5) – Intermediate proficiency – 16 – Advanced proficiency – 22 Late English-Spanish bilinguals (age of acquisition of Spanish > 11) – Intermediate proficiency – 52 – Advanced proficiency – 18

33 Experiment 2: Materials Language history questionnaire Proficiency test(s) Experimental task – Modified sentence-fragment completion task

34 Experiment 2: Stimuli & Procedure Same as Experiment 1 – Completed in both English and Spanish – different list each time, sessions at least 1 week apart

35 Experiment 2 Results: Manner Are English-Spanish bilinguals sensitive only to grammatical number when producing English? The label on the bottles are… > The bus to the schools are…

36 Experiment 2 Results: Manner Are English-Spanish bilinguals sensitive to conceptual number when producing Spanish? The label on the bottles are… > The bus to the schools are…

37 Experiment 2 Research questions: Manner Do English-Spanish bilinguals produce subject-verb number agreement in the same manner in both languages? – YES What role do age of acquisition and proficiency play in bilingual agreement production? – Manner NONE…all groups are sensitive to conceptual number in both Spanish and English

38 Experiment 2 Discussion: Manner Results support NO cross-linguistic differences in how bilinguals produce agreement…conceptual number affects agreement processes in both English and Spanish regardless of age of acquisition or proficiency level. – In terms of the maximalist model (Vigliocco, Butterworth, & Garrett, 1996), bilinguals effect agreement by means of feature unification in both of their languages, no matter the AoA or proficiency level

39 Experiment 2 Results: Accuracy – AoA Are early bilinguals more accurate in agreement production than late bilinguals?

40 Experiment 2 Results: Accuracy – Proficiency Are advanced bilinguals more accurate in agreement production than intermediate bilinguals?

41 Experiment 2 Research questions: Accuracy What role do age of acquisition and proficiency play in agreement production in English-Spanish bilinguals’ two languages? – Accuracy More proficient bilinguals are more accurate, no matter whether late or early Early bilinguals less accurate than late bilinguals

42 Experiment 2 Discussion: Accuracy Advanced proficiency bilinguals more accurate than intermediate proficiency bilinguals Early bilinguals NOT more accurate than late bilinguals…other way around. – Contrary to an across-the-board interpretation of the CPH

43 Central question in SLA Why is the outcome of second language (L2) acquisition different from that of first language (L1) acquisition? – Variability in late bilingual production of agreement morphology – Psycholinguistic processes of language production (performance) as a source of the variability The aspects of the agreement production system investigated are not responsible for the variability at the level of inflectional morphology present in bilinguals Is there really a problem with morphological variability in late bilingual agreement production? – Subject-verb number agreement vs. adjective agreement Adjective agreement in Spanish: La etiqueta en las botellas es roja.

44 Subject-verb number agreement vs. adjective agreement errors

45 Conclusion Age effects in second language acquisition should be investigated in terms of specific linguistic structures or psycholinguistic processes Younger may not always be better!

46 Acknowledgements Silvina Montrul J. Kathryn Bock Ann Abbott Melissa Bowles Jonathan Foote Justin Davidson Dept. of Spanish, Italian, and Portuguese, University of Illinois at Urbana-Champaign University of Illinois Graduate College

47 Thank you! Questions? Comments?