1. Ken Beesley / 7 Aug 2001 / page 1 One Working Linguist’s View of Two-Level Morphology Ken Beesley, Xerox Research Centre Europe

2. Ken Beesley / 7 Aug 2001 / page 2 Two-Level Morphology and its Offspring have been Successfully Applied to a Wide Variety of Languages from all over the World Finnish, Swedish, French, EnglishFinnish, Swedish, French, English Spanish, Rumanian, Russian, Polish, German, …Spanish, Rumanian, Russian, Polish, German, … Japanese, Turkish, Korean, AymaraJapanese, Turkish, Korean, Aymara SwahiliSwahili Current work: Basque, Zulu, Irish, …Current work: Basque, Zulu, Irish, … No other morphological theory/tradition has resulted in so many practical, working applications.

3. Ken Beesley / 7 Aug 2001 / page 3 My Own Exposure to Two-Level Morphology Lauri Karttunen’s Two-Level Tutorial at COLING 88 in BudapestLauri Karttunen’s Two-Level Tutorial at COLING 88 in Budapest Led to the 1988 ALPNET implementation (in Common Lisp, later C)Led to the 1988 ALPNET implementation (in Common Lisp, later C) Based on published sourcesBased on published sources –Koskenniemi 1983 “Two-Level Morphology: a general computational model for word-form recognition and production” –Fred Karlsson (ed.) 1985, “Computational Morphosyntax: Report on Research 1981-1994” –Dalrymple et al. 1983, “Texas Linguistic Forum, Vol. 22.”, Dept. of Linguistics, Univ. of Texas at Austin. (The “KIMMO” implementation.)

4. Ken Beesley / 7 Aug 2001 / page 4 Implementations of Two-Level Morphology Many around the world, often inspired by the KIMMO implementationMany around the world, often inspired by the KIMMO implementation Evan Antworth’s 1990 “PC-KIMMO: a two-level processor for morphological analysis” was especially accessible and well documentedEvan Antworth’s 1990 “PC-KIMMO: a two-level processor for morphological analysis” was especially accessible and well documented AugmentationsAugmentations –Feature-checking and feature unification (ALPNET, Bear, Trost, etc.) –(ALPNET) enhanced dictionary traversal (“detouring”) allowing two sublexicon trees to be traversed together at runtime, used to intersect Semitic roots and patterns into stems

5. Ken Beesley / 7 Aug 2001 / page 5 Often claimed that Two-Level Morphology is unsuited for some kinds of languages, especially Semitic languages, but … Kay 1987 “Nonconcatenative Finite-State Morphology”Kay 1987 “Nonconcatenative Finite-State Morphology” –Arabic, influenced by McCarthy (1981), using multi-level transducers Kataja & Koskenniemi, 1988 “Finite-state Description of Semitic Morphology: A Case Study of Ancient Akkadian”Kataja & Koskenniemi, 1988 “Finite-state Description of Semitic Morphology: A Case Study of Ancient Akkadian” –Comparative grammars of Neo-Assyrian and Neo-Babylonian, with root-pattern “intersection” via a pre-processing step Lavie, Itai, Ornan & Rimon 1988, “On the Applicability of Two Level Morphology to the Inflection of Hebrew Verbs”Lavie, Itai, Ornan & Rimon 1988, “On the Applicability of Two Level Morphology to the Inflection of Hebrew Verbs” –Hebrew, with a “preliminary stage” that combines roots and patterns

6. Ken Beesley / 7 Aug 2001 / page 6 Two-Level Morphology and Semitic languages, continued Beesley 1989, “Computer Analysis of Arabic Morphology: A Two-Level Approach with Detours” (and several follow-up papers)Beesley 1989, “Computer Analysis of Arabic Morphology: A Two-Level Approach with Detours” (and several follow-up papers) –Arabic, with runtime intersection of roots and patterns (later converted to the Xerox finite-state implementation, with root-pattern intersection at compile time) Kiraz 1994, “Multi-Tape Two-Level Morphology” (and several follow-up papers)Kiraz 1994, “Multi-Tape Two-Level Morphology” (and several follow-up papers) –Syriac, influenced by Kay, McCarthy, Grimley-Evans/Kiraz/Pulman implementation In the 21 st Century, there is continued interest in finite-state handling of non- concatenative phenomena: Semitic interdigitation, reduplication, infixation

7. Ken Beesley / 7 Aug 2001 / page 7 Two-Level Morphology has been a Success Around the World and Beyond! 1985, “The Klingon Dictionary: English/Klingon, Klingon/English” Ken Beesley 1992a “Klingon Two-Level Morphology, Part 1: Nouns”, HolQeD 1:2 1992b “Klingon Morphology, Part 2: Verbs”, HolQeD 1:3 Thought to be the first successful application of Two-Level Morphology (PC- KIMMO implementation) to a non-human, extraterrestrial natural language. Qapla’! (“success”) Marc Okrand