to prove / detect
Loading your saved state.
to prove
To establish the existence or truth of something through evidence or facts.
Der Anwalt konnte die Unschuld seines Mandanten zweifelsfrei nachweisen.
The lawyer was able to prove his client's innocence beyond doubt.
'Nachweisen' (to prove/detect) is a separable verb. The prefix 'nach-' goes to the end in a main clause. In subordinate clauses and in the infinitive with 'zu', the verb stays together.
Die Polizei wies ihm die Tat nach.
The police proved that he committed the crime.
The verb consists of the prefix 'nach-' and the verb 'weisen' (to show/point). The meaning 'beweisen' (to prove) comes from the idea of pointing to a fact or piece of evidence afterward.
Der Forscher konnte seine Theorie mit Daten nachweisen.
The researcher was able to prove his theory with data.
When you prove something against or to a person with 'nachweisen' (to prove), that person is in the dative. The thing being proven is in the accusative. The pattern is: jemandem (dative) etwas (accusative) nachweisen.
Man konnte dem Verdächtigen den Diebstahl nicht nachweisen.
They could not prove that the suspect committed the theft.
This meaning is typical in scientific, medical, or chemical contexts. You can recognize it from objects such as 'eine Substanz' (a substance), 'ein Virus' (a virus), 'Spuren' (traces), or 'ein Giftstoff' (a toxin).
Im Trinkwasser wurden Spuren von Bakterien nachgewiesen.
Traces of bacteria were detected in the drinking water.
to show
'zeigen' and 'nachweisen' can both mean that something is made clear or credible. 'zeigen' is more general and can also happen through an example, a number, or a situation. 'nachweisen' is more specific: you prove something with clear facts, documents, tests, or evidence. In medicine and science, 'nachweisen' sounds especially natural. Learners may confuse the words because both have to do with evidence. When it is about solid proof, 'nachweisen' fits better; when something simply becomes clear, 'zeigen' is often enough.
Der Arzt konnte die Infektion durch einen Test nachweisen.
The doctor was able to detect the infection with a test.
Die neuen Zahlen zeigen, dass viele Kunden zufrieden sind.
The new figures show that many customers are satisfied.