Ageing as a field of research

German keeps apart two nouns that English folds into one. Das Alter is age, and above all old age as a stage of life; das Altern is the verb altern turned into a noun, and names the process. In a compound the difference survives as a single letter. A nominalised infinitive normally takes a linking -s — das Leben gives die Lebensqualität, das Wissen gives der Wissensstand — so das Altern gives die Alternsforschung: research into a process that starts long before retirement. Die Altersforschung, built on das Alter, can be read as research into the old. Everyday German often treats the two as interchangeable; the field itself tends to choose. The same letter separates altersgerecht, suited to older people, from alternsgerecht, which describes work designed to suit people at every stage of a working life. Read the n before you read the rest of the word.