Nominalization is the use of a verb adjective or an adverb as a noun. It can be done in two ways:

i) Add something to the word to make a noun
  Eg. Combine(verb) ==> Combination
        Difficult(adjective) ==> Difficulty
        Run(verb) ==> Running

ii)Use the same word as a noun
  Eg. Change is a verb and a noun
        Murder is a verb and a noun
Thank you for explaining Megusta.
no probs