peer reviewed ; This article provides an overview of the structure of the Luxembourgish language, the national language of the Grand Duchy of Luxembourg, which has developed from a Moselle Franconian dialect to an Ausbau language in the course of the 20th century. In the early 21st century, Luxembourgish serves several functions, mainly as a multifunctional spoken variety but also as a written language, which has acquired a medium level of language standardization. Because of the embedding into a complex multilingual situation with German and French, Luxembourgish is characterized by a high degree of language contact. As a Germanic language, Luxembourgish has developed its distinct grammatical features. In this article, the main aspects of phonetics and phonology (vowels, consonants, prosody, word stress), morphology (inflection of nouns, adjectives, articles and pronouns, partitive structures, prepositions, verbal system), and syntactic characteristics (complementizer agreement, word order in verbal clusters) are discussed. The lexicon is influenced to a certain degree by loanwords from French. Regarding language variation and change, recent surveys show that Luxembourgish is undergoing major changes affecting phonetics and phonology (reduction of regional pronunciations), the grammatical system (plural of nouns), and, especially, the lexical level (decrease of loans from French, increase of loans from German).