Ergänzung (f)
/ɛɐ̯ˈɡɛntsʊŋ/
'Ergänzung' refers to something added to an existing whole in order to complete or enrich it. The right English equivalent depends heavily on context: whether everyday speech, grammar, nutrition, or legal documents.
1. addition
The broadest equivalent for something added to an existing whole, equally at home in everyday, professional, and written contexts.
2. supplement
Used when the addition fills a gap or enriches a primary product: typical in nutrition, publishing, and periodicals.
3. complement [technical] · grammar, mathematics
Technical term in grammar (obligatory sentence element) and mathematics (complement set); also used when two things complete each other perfectly.
4. addendum [formal] · legal
In contract and document law: a subsequent addition appended to a document without altering the original text.
Notes
In German grammar instruction, 'Ergänzung' specifically denotes an obligatory sentence element required by the verb, whereas 'Angabe' covers optional modifiers (a distinction English 'complement' does not neatly replicate). In nutritional contexts, 'supplement' is always the correct English choice; 'complement' would be a clear register error.