LuxBorrow: From Pompier to Pompjee, Tracing Borrowing in Luxembourgish

TL;DR

This study analyzes 27 years of Luxembourgish news to understand borrowing patterns, revealing persistent multilingual practices, dominant French influence, and evolving morphosyntactic adaptations through a comprehensive computational pipeline.

Contribution

It introduces LuxBorrow, a novel pipeline combining language identification and borrowing resolution to analyze lexical borrowing and code-switching in Luxembourgish news over time.

Findings

LU remains the matrix language across all documents.

Multilingual practice is pervasive with most articles containing multiple languages.

Morphological and orthographic adaptations are the primary forms of borrowing.

Abstract

We present LuxBorrow, a borrowing-first analysis of Luxembourgish (LU) news spanning 27 years (1999-2025), covering 259,305 RTL articles and 43.7M tokens. Our pipeline combines sentence-level language identification (LU/DE/FR/EN) with a token-level borrowing resolver restricted to LU sentences, using lemmatization, a collected loanword registry, and compiled morphological and orthographic rules. Empirically, LU remains the matrix language across all documents, while multilingual practice is pervasive: 77.1% of articles include at least one donor language and 65.4% use three or four. Breadth does not imply intensity: median code-mixing index (CMI) increases from 3.90 (LU+1) to only 7.00 (LU+3), indicating localized insertions rather than balanced bilingual text. Domain and period summaries show moderate but persistent mixing, with CMI rising from 6.1 (1999-2007) to a peak of 8.4 in 2020. Token-level adaptations total 25,444 instances and exhibit a mixed profile: morphological 63.8%, orthographic 35.9%, lexical 0.3%. The most frequent individual rules are orthographic, such as on->oun and eur->er, while morphology is collectively dominant. Diachronically, code-switching intensifies, and morphologically adapted borrowings grow from a small base. French overwhelmingly supplies adapted items, with modest growth for German and negligible English. We advocate borrowing-centric evaluation, including borrowed token and type rates, donor entropy over borrowed items, and assimilation ratios, rather than relying only on document-level mixing indices.