Sources and level guidance

The C1 extension adds 10,000 distinct German headwords: 6,500 nouns, 1,800 verbs, 1,400 adjectives and 300 adverbs. None repeats an A1–B2 headword under our article, lemma and spelling-variant comparison.

What the C1 label means

This is an editorial collection for advanced and specialist practice. It also fills useful gaps in earlier levels. A word’s difficulty depends on its meaning and context; not every entry is inherently C1. The collection is not an official examination list and has not been independently CEFR certified or fully teacher reviewed.

Council of Europe descriptors describe communicative ability. Memorising a fixed number of words does not establish that ability.

C1 dictionary data

The English definitions and noun genders are adapted from English Wiktionary contributors, extracted through Kaikki / Wiktextract by Tatu Ylonen from the 2 September 2026 dump. Each C1 library card links to its original German dictionary entry and contributor history.

We select one usable standard sense, shorten terminal punctuation, filter inflections, alternate spellings and marked nonstandard senses, and make targeted corrections. Some entries have multiple genders or meanings; the card teaches its selected sense. Definitions and the adapted C1 lexical dataset are available under Creative Commons Attribution–ShareAlike 4.0. This notice applies to that lexical data, separately from the application code.

wordfreq 3.1.1, by Robyn Speer and contributors, supplies usage estimates for selection. These are frequency estimates, not CEFR ratings. We also use the MIT-licensed Tartarus C1 list by Bahman Farhadian to prioritise matching headwords.

Earlier vocabulary

The B1 extension and B2 collection draw on Tartarus under its MIT licence. Earlier cards and their progress identities are retained.

Import method and review limits · Full credits and licences · Adapted C1 data