# UniMorph 4.0: Universal Morphology

arXiv: https://arxiv.org/abs/2205.03608 · HTML: https://mlsanity.com/paper/2205.03608/

## Key facts

- Cited by 11 papers in the map (data through 14 Oct 2026).
- Builds on 12 of its 111 references that are in the map.
- First posted on arXiv 7 May 2022.

## Builds on (most cited first, 12 of 12)

- [Neural Machine Translation of Rare Words with Subword Units](https://mlsanity.com/paper/1508.07909/) (2015)
- [Between words and characters: A Brief History of Open-Vocabulary Modeling and Tokenization in NLP](https://mlsanity.com/paper/2112.10508/) (2021)
- [The SIGMORPHON 2019 Shared Task: Morphological Analysis in Context and Cross-Lingual Transfer for Inflection](https://mlsanity.com/paper/1910.11493/) (2019)
- [UniMorph 2.0: Universal Morphology](https://mlsanity.com/paper/1810.11101/) (2018)
- [The CoNLL--SIGMORPHON 2018 Shared Task: Universal Morphological Reinflection](https://mlsanity.com/paper/1810.07125/) (2018)
- [CoNLL-SIGMORPHON 2017 Shared Task: Universal Morphological Reinflection in 52 Languages](https://mlsanity.com/paper/1706.09031/) (2017)
- [SIGMORPHON 2020 Shared Task 0: Typologically Diverse Morphological Inflection](https://mlsanity.com/paper/2006.11572/) (2020)
- [Marrying Universal Dependencies and Universal Morphology](https://mlsanity.com/paper/1810.06743/) (2018)
- [Automatic Identification of Closely-related Indian Languages: Resources and Experiments](https://mlsanity.com/paper/1803.09405/) (2018)
- [Morphological Reinflection with Multiple Arguments: An Extended Annotation schema and a Georgian Case Study](https://mlsanity.com/paper/2203.08527/) (2022)
- [Morpheme Boundary Detection & Grammatical Feature Prediction for Gujarati : Dataset & Model](https://mlsanity.com/paper/2112.09860/) (2021)
- [A Resource for Studying Chatino Verbal Morphology](https://mlsanity.com/paper/2004.02083/) (2020)

## Built on by (most cited first, 11 of 11)

- [MultiBLiMP 1.0: A Massively Multilingual Benchmark of Linguistic Minimal Pairs](https://mlsanity.com/paper/2504.02768/) (2025)
- [The SIGMORPHON 2022 Shared Task on Morpheme Segmentation](https://mlsanity.com/paper/2206.07615/) (2022)
- [CompoundPiece: Evaluating and Improving Decompounding Performance of Language Models](https://mlsanity.com/paper/2305.14214/) (2023)
- [K-UniMorph: Korean Universal Morphology and its Feature Schema](https://mlsanity.com/paper/2305.06335/) (2023)
- [Lexical Diversity in Kinship Across Languages and Dialects](https://mlsanity.com/paper/2308.13056/) (2023)
- [Morphological Inflection: A Reality Check](https://mlsanity.com/paper/2305.15637/) (2023)
- [LLMs' morphological analyses of complex FST-generated Finnish words](https://mlsanity.com/paper/2407.08269/) (2024)
- [Corpus Frequencies in Morphological Inflection: Do They Matter?](https://mlsanity.com/paper/2510.23131/) (2025)
- [GLeMM: A large-scale multilingual dataset for morphological research](https://mlsanity.com/paper/2604.12442/) (2026)
- [SuTRA : Structurally-Unified Tokenization with Root Awareness](https://mlsanity.com/paper/2608.18087/) (2026)
- [Shared Circuits for Shared Grammar: Tracing Subject-Verb Agreement Across Languages](https://mlsanity.com/paper/2608.18545/) (2026)

## Abstract (arXiv)

The Universal Morphology (UniMorph) project is a collaborative effort providing broad-coverage instantiated normalized morphological inflection tables for hundreds of diverse world languages. The project comprises two major thrusts: a language-independent feature schema for rich morphological annotation and a type-level resource of annotated data in diverse languages realizing that schema. This paper presents the expansions and improvements made on several fronts over the last couple of years (since McCarthy et al. (2020)). Collaborative efforts by numerous linguists have added 67 new languages, including 30 endangered languages. We have implemented several improvements to the extraction pipeline to tackle some issues, e.g. missing gender and macron information. We have also amended the schema to use a hierarchical structure that is needed for morphological phenomena like multiple-argument agreement and case stacking, while adding some missing morphological features to make the schema more inclusive. In light of the last UniMorph release, we also augmented the database with morpheme segmentation for 16 languages. Lastly, this new release makes a push towards inclusion of derivational morphology in UniMorph by enriching the data and annotation schema with instances representing derivational processes from MorphyNet.