Present, Future 難い is [x] 難くない is not [x] Past 難かった was [x] 難くなかった was not [x] Te-form, Continuative 難くて is [x] and... 難くなくて is not [x] and... Provisional 難ければ if it is [x] 難くなければ if it is not [x] Conditional 難かったら when/if it is [x] 難くなかったら when/if it is not [x] Adverbial 難く [x]-ly Noun form 難さ [x]-ness