Word formation

predict - adverb

• prediction
• predictable
• predictor
• predicate

predictable - antonym

• impredictable
• irpredictable
• unpredictable
• dispredictable

understand - antonym

• disunderstand
• ununderstand
• irunderstand
• misunderstand

revise - noun

• revision
• revised
• rerevise

thank - adjective

• thankful
• thankfully
• thanks
• thankfulness

appear - antonym

• misappear
• disappear
• reappear
• unappear

sad - noun

• sadly
• sadlessness
• sadness

humour - adjective

• humour
• humourist
• humourous

popular - antonym

• impopular
• inpopular
• unpopular
• non-popular

helpless - antonym

• helplessness
• unhelpless
• inhelpless
• helpful