The Swedish translation of “heavy” is usually “tung”. For a phrase like “heavy heavy heavy,” you can repeat it as “tung, tung, tung”.

Notes

  • tung = heavy in the physical sense.
  • In some contexts, heavy can also mean svår (difficult), mäktig (powerful/weighty), or bekymmersam depending on meaning.
  • If you meant the sentence “heavy heavy heavy said how,” that exact phrase is not a natural Swedish sentence, so I’d need the full intended meaning to translate it cleanly.