Which part of speech is used to express an action or state of being?

The correct answer is a verb. Verbs are essential in language as they serve to convey actions, occurrences, or states of being. For example, in the sentence "She runs every morning," "runs" indicates the action the subject is performing. Similarly, in "He is tired," the verb "is" expresses the state of being.

Understanding the role of verbs helps in constructing meaningful sentences, as they provide clarity about what is happening or what someone is experiencing. Recognizing verbs in sentences also aids learners in improving their writing skills, as using a variety of action words can enhance the dynamism and engagement of their writing.