Nachweis

Nachweis is a German noun meaning proof, evidence, or demonstration that something is the case. It denotes a piece of evidence or documentation that establishes a fact, claim, or condition. The word derives from nachweisen, to prove or demonstrate, from nach- (toward, after) and weisen (to point).

In scientific and medical contexts, Nachweis often refers to detection or demonstration of a substance or condition, such as a qualitative Nachweis of a compound, a diagnostic Nachweis, or the Nachweisgrenze (limit of detection). In chemistry, a Nachweisreaktion is a test that confirms the presence of a substance. In law and administration, Nachweis specifies the proof a party must provide to support a claim, such as Nachweis der Identität or Nachweis des Anspruchs; Beweis is a broader term for evidence, while Nachweis denotes the specific evidence presented.

In everyday language, Nachweise can be documents or certificates that verify a condition, such as a passport as Nachweis der Identität or a certificate as Nachweis von Sprachkenntnissen. The concept is also common in education and employment as the required proof of qualifications. The plural Nachweise is standard in German usage. In translation, Nachweis is commonly rendered as “proof” or “evidence,” with context determining whether it refers to detection, documentation, or formal proof.