the study of the derivational words from 200 years till now, from the motivational point of view

a motivated derivational word is a word that its meaning is the result of the meaning of word stem and derivational affixes. in this paper, the hypothesis is tested that by the passage fo time,motivation would be reduced and for this purpose, four itinerary passages from present and four equal passages from 200 years before are chose to understand ,under comparisons and statistical considerations, from 200 years befor, derivational words in persian language have been more motivated or not. comparison of results show that a meaningful increase is evident in the number of derivational words in present time, in the number of motivated words and in the number of partially motivated derivational words .therefore,we would say that from two hundred years before, derivational words in persian language have been more motivation.