The process of identifying and highlighting verbs and subjects in sentences proved to be a relatively challenging task

The process of identifying and highlighting verbs and subjects in sentences proved to be a relatively challenging task. Even so, I could easily identify verbs, but the process of underlining them seemed to be a tedious act. On the other hand, the practice of identifying subjects in sentences was more challenging since I had to disregard particular nouns while determining the ones that serve as the subjects of the sentences.