nachforschen

You use it as a verb. It often stands alone or takes a prepositional object with nach. For example: Ich muss nachforschen. It is a separable verb in some contexts, but usually, you see it as one piece. Use it when you are playing detective. It works for lost mail or complex science. It feels proactive and intelligent.

Use it when a mystery needs solving. Use it at work when a report is missing. Use it when a friend tells a weird story and you want the truth. It is perfect for professional emails. It also fits when you are curious about your family history. It sounds much more thorough than just suchen (to search).

Do not use it for simple physical searches. If you lost your keys on the sofa, do not say nachforschen. That is just suchen. Do not use it for casual browsing. If you are just looking at shoes online, this word is too heavy. It sounds like a police investigation if used for trivial things. Avoid it for 'googling' a quick recipe.

Germans value thoroughness and 'Gründlichkeit'. Nachforschen reflects this cultural trait perfectly. It suggests you are not satisfied with surface-level answers. Historically, it links to the German tradition of deep academic inquiry. It is the word of a society that loves rules, logic, and finding the root cause. It is a very 'reliable' sounding word.

You will often hear Nachforschung as a noun. People say Nachforschungen anstellen. This means 'to conduct investigations'. It sounds a bit more official. Another variation is hinterherforschen. This is slightly more informal. It implies following a trail or even 'snooping' a little bit. Stick to nachforschen for a balanced, smart tone.