The subject of a verb is the person or thing which performs the action of the verb. For example: I left the room. - Here, the verb is 'left' and the act of leaving was performed by 'I'. Hence, 'I' is the subject. The object of the verb is the person or thing affected by the verb. For example: She spoke to John. - Here, the action of the verb (spoke) is being done on John. Hence, 'John' is the object.