The German word for “useless” is “nutzlos”. Related in meaning are “unbrauchbar” (“unusable”), “zwecklos” (“pointless”) “sinnlos” (“senseless” or “meaningless”), “wertlos” (“worthless”) and “vergeblich” (“futile”):

– “Die kaputte Uhr ist komplett nutzlos.” – “The broken clock is completely useless.”
– “Steh nicht so nutzlos herum!” – “Don’t stand around so uselessly!”
– “Diese alten Informationen sind unbrauchbar.” – “This old information is unusable.”
– “Gib es auf. Es ist zwecklos.” – “Give it up. It’s pointless.”
– “Es war ein sinnloses Verbrechen.” – “It was a senseless crime.”
– “Dieser Pfennig ist jetzt wertlos.” – “This Pfennig is worthless now.”
– “Ich habe es vergeblich versucht.” – essentially “My attempts were futile.” or “I tried it unsuccessfully.”

The opposite of “nutzlos” is “nützlich”. The word “nutzvoll” does not exist (and neither does “zweckvoll”), although “sinnvoll” (“sensible”) and “wertvoll” (“valuable”) do. The opposite of “unbrauchbar” is “brauchbar” (“usable”).