The present study analyzes the problems in learning English words through words formation processes by undergraduate students. The instrument of the test was used to collect data from one hundred seventeen undergraduate students selected through non-random convenient sampling. The findings of the study suggest that students had not acquired most of the English words through word-formation processes. The words formed through conversion, backformation, compounding and acronym were acquired less in number by students than the blending and abbreviation. The results show that undergraduate students had no significant difficulty in learning English common suffixes deriving English words as compared to the non-common ones. The common, occurring prefixes and suffixes forming new words were both difficult, but the suffixes were a bit more difficult than prefixes, while the non-common occurring prefixes and suffixes forming new words were both equally difficult for students. The idiomaticity of the words makes them difficult to learn.