Child preference of base correspondence

1. UMMM, Nov. 1. 2009 MIT Young Ah Do (youngah@mit.edu) Child preference of base correspondence

2. Children vs. Adults-Regular verb inflection • aki-ka ca-n-ta. (children & adults) • baby-nom sleep-present-decl.

3. Children vs. Adults-Irregular verb inflection • kangmuɾ-i hɨɾɨ-n-ta. (adults) • river-nom flow-present -decl. • kangmuɾ-i hɨllə-o-n-ta. (children) • river-nom flow -toward-present-decl.

4. Overview • The child inflection of irregular verb is complex. • They do have excellent knowledge of the whole inflectional system. • The preference of more complex inflection especially for irregular verbs is to satisfy high ranked output-output correspondence.

5. Verbal suffixes • Three categories of suffixes • A: -ɑ/-ə initial suffixes • tak’-ɑ (to clean), mək-ə (to eat), kɑ-ɑ> kɑ (to go) • B/C: -ɨ/consonant initial suffixes • tak’-ɨni, mək-ɨni, ka-ni • tak’-k’o, mək-k’o, ka-ko

6. Functions of each suffixal category • A : mood morpheme or semantically empty • -ɑ/ə • mək-ə: declarative, interrogative, imperative • -ɑ/ə + tense+ mood • mək-ə-ss-t’a : ate • -ɑ/ə + aspectual + mood • mək-ə-po-ta : try eating

7. Functions of each suffixal category • B/C: clausal or mood morpheme • -ɨni: causal • mək-ɨni: Since (I) eat …, / eat … therefore, • -ɨmyən: conditional • mək-ɨmyən: if (I) eat …, • -ko: connective • mək-k’o: eat and • -ta: declarative • mək-t’a: eat • -ni: question • mək-ni? : Do (you) eat… ?

8. The shape of stems Regulars vs. Irregulars • Regular verbs • Same stem across different suffixes • A: tak’-ɑ B: tak’-ɨni C: tak’-k’o (to clean) • Irregular verbs • Different stems with respect to the suffixal categories • A: tow-ɑ B: tou-ɨni >touni C: top-k’o ( to help)

9. Overuse of A form • Innovative patterns are frequently observed from the inflection of irregular verbs. • Innovations are mostly based on the A form. (Kang 2006, Bak 2004, Park 2002, and AKS 1990-1995). • hæ, ha-ni, ha-ko (to do) • => hæ, hæ-ni, hæ-ko • tow-ɑ, tou-ni, top-k’o (to help) • => tow-ɑ, tow-ni, tow-ko

10. Overuse of A form-Hypothesis 1 • High frequency • In adult Korean, A form mood marker functions as a default mood marker, in the respect that it is in free alternation with more specific mood markers. (Kim and Philip 1998) • Children hear A form most frequently in the early age. (Lee et al. 2003)

11. Overuse of A form- Hypothesis 2 • Base dependency • Computational modeling of learning (Albright and Kang 2009) using Minimal Generalization Learner algorithm (Albright and Hayes 2002, 2003) • Higher predictability of the paradigm from A form than from B or C form.

12. Predictions from two hypotheses • Frequency effect (Hypothesis 1) predicts that children will overuse A form both for regular and irregular verb inflection. • Base dependency (Hypothesis 2) predicts that children will overuse A form for irregular verb inflection but not for regular one. • The current study will support hypothesis 2.

13. An Experiment • Picture description, asking the inflection of the verbs. • jəca-nɨn _______. • A woman-NOM _____. (expected answer: declarative form of ‘sing’)

14. The design of an experiment • (1) The context where either B or C suffix forms can be observed • Sentence co-ordinating conjunction

15. (1) B or C suffixation • Sentence co-ordinating conjunctions are realized by the suffixation of B or C suffix after verb stem in Korean. • -ko (C suffix) ‘and‘ • Jane-ɨn ca-ko John-ɨn cʰumcʰu-n-ta. • Jane-NOM sleep-and John-NOM dance-present-decl.

16. More examples • -ko (C suffix), -ɨmyə (B suffix) ‘and’ • top-k’o ‘help and … ‘ • tou-myə(<tou-ɨmyə) ‘help and … ‘ • -ciman (C suffix), -ɨna (B suffix) ‘but’ • top-ciman ‘help but … ‘ • tou-na(<tou-ɨna) ‘help but … ‘ • -kəna (C suffix) ‘or’ • top-kəna ‘help or … ‘

17. Tense marker and conjuncts • Tense morpheme is allowed only at final clause. • Stem-conjunct, stem-tense-decl • ka-ko, o-n-ta (go-and, come-present-decl) • * ka-n-ko, o-n-ta (go-present-and, come-present-decl) • *ka-ko, o-ta (go-and, come-decl) • *ka-n-ko, o-ta (go-present-and, come-decl) • ka-ko, o-a-ss-t’a (go-and, come-a-past-decl-> went and came) • Let us assume empty tense marker before conjunct • [ø-conj], [tense-decl]

18. (2) Regular vs. Irregular • Regular and irregular verbs are distributed in a coordinated sentence as a pair. • Stimuli • Subject ___(regular verb), subject ___ (irregular verb). & • Subject ___(irregular verb), subject ___ (regular verb).

19. An example of stimuli • Namcatul-un ______, jəcatul-un ____. • Men-nom ______, women-nom ____. • expected answer: run/walk, are running/ are walking…

20. Subjects • 8 children (4;2~7;9) • 5 girls and 3 boys • Having morphophonological knowledge of the verb inflection • Able to inflect verbs with all three categories of suffixes • 4 adults

21. The design of stimuli • Among 159 irregular verbs in Korean • 54 verbs which seem to be familiar to children were chosen. • easy and frequent verbs • 54 sentences • #27 <irregular, regular> • #27 <regular, irregular>

22. Result • Among 54 sentences, 30 cases are analyzed where all subjects give same description of the picture. • #18 <Reg, Irreg>, #12 <Irreg, Reg> • This picture is described as • A girl reads a book. • A girl studies. • ….

23. Result- Parallel structure of two verbs • Two verbs in a coordinated sentence are inflected in a parallel way. • talli-[ø-ko], kət-[nɨn-ta] • run-[ø-and], walk-[present-decl] • kəɾ-ə-[ka-ø-ko], talli-ə-[o-n-ta] • walk-[away-ø-and], run-[toward-present-decl] • DEP-C1C2, MAX-C1C2

24. Result- Child errors • A forms are used where B/C forms are required. • cup-nɨn-ta (pick-present-decl) • -> *cuw-n-ta • No case where B/C forms substitute A form. • kəɾ-ə-ka-n-ta (walk-away-present-decl) • -> * kət-ka-n-ta

25. Result-Child errors • Why do children overuse A form? • Frequency effect? • Base dependency?

26. Result- Asymmetry of the inflection • The preferred way of inflection is different according to the pair <REG, IRREG> and <IRREG,REG>.

27. Result- Asymmetry of the inflection • <REG,IRREG> • without aspectual morphemes • talli-ko, kət-nɨn-ta • run-[ø-and], walk-[present-decl] • <IRREG,REG> • with aspectual morphemes • kəɾ-[ə-ka-ø-ko], talli-[ə-ka-n-ta] • walk-[away-ø-and], run-[away-present-decl]

28. Result- Asymmetry of the inflection

29. Process of structuring • Syntactic and semantic form is preliminarily planned both for 1st and 2nd conjuncts. • When 1st conjunct is planning phonological form, 2nd conjunct has syntactic form but not phonological form yet. • The phonological form of 2nd conjunct is inserted later by copying that of the 1st conjunct.

30. Process of structuring

31. Syntactic/Semantic planning • The context determines the number of clauses and the position of conjunct/mood morpheme. • ____-TENSE-CONJUNCT, ____-TENSE-MOOD MORPHEME. • Semantic interpretation determines verb stems, tense markers, conjuncts and mood morphemes. • RUN-PRESENT-BUT, WALK-PRESENT-DECLARATIVE. • RUN TOWARD-PRS-BUT, WALK AWAY-PRS-DECL.

32. Syntactic/Semantic planning • The economy of the production • Unless speakers think aspectual morpheme is semantically necessary, they will not use aspectual morpheme for the economy of the production. • RUN-PRESENT-BUT, WALK-PRESENT-DECLARATIVE. • Let us call the form planned by syntactic and semantic consideration as “Target” (the target of the production).

33. Phonological planning-1st conjunct • Assuming the hypothesis that (a) A form is the base in Korean verbal paradigms (Albright and Kang 2009), and (b) children start out with high-ranking OO Faithfulness (McCarthy 1999, Hayes 2004), children modify the target if it violates base derivative identity (BD-ID) while adults do not.

34. Phonological planning-1st conjunct • In this process, they seek a way of modification which is semantically closest to the target. Let us call a modified form as “Realize”. • In other words, “Realize” should have minimal violation to the “Target”. • In the current picture description task, children insert an aspectual morpheme which enables more specific description of the context, with keeping the original meaning of “Target”.

35. Phonological planning of 1st conjunct • The inflection of regular verb 35

36. Phonological planning of 1st conjunct • The inflection of irregular verb

37. Phonological planning of 2nd conjunct • After the phonological form is determined in 1st conjunct, 2nd conjunct copies the same structure in order to make structural parallelism in a coordinated sentence. • DEP-C1,C2 • Every morpheme of conjunct 2 has a correspondence in conjunct 1 • MAX-C1,C2 • Every morpheme of conjunct 1 has a correspondence in conjunct 2

38. Phonological planning of 2nd conjunct • When the 1st conjunct is regular verb 38 38

39. Phonological planning of 2nd conjunct • When the 1st conjunct is irregular verb 39 39 39

40. Phonological planning in coordinated sentences • The choice of using A or B/C form is determined by the first conjunct in coordinated sentences. • The shape of the second verb is determined by the requirement of parallelism (i.e., to be identical to the shape of the first verb).

41. Base correspondence • When regular verb is to be inflected in 1st conjunct, any inflection can satisfy base correspondence because the stem is identical across different suffixations. • When irregular verb is to be inflected in 1st conjunct, inflection depending on B/C form violates base correspondence while that on A form does not. • Therefore, children use excessive morpheme especially for irregular verb inflection for satisfying high-ranked output-output faithfulness.

42. Implication • The asymmetrical inflectional patterns with respect to the (ir)regularity of the verb argue that overuse of A form is triggered not by high frequency effect but by grammatical consideration: high-ranked output-output faithfulness.