Spell checking dictionaries are not installed always by default.
So if your Koffice or Kword are not able to check spelling, all you have to do is to download though Synaptic: Ispell, Aspell or Myspell dictionaries, in the language of your interest.
Tips & Tricks / Howtos
Forum rules
Don't add support questions to tutorials; start your own topic in the appropriate sub-forum instead. Before you post read forum rules
Don't add support questions to tutorials; start your own topic in the appropriate sub-forum instead. Before you post read forum rules