The sentence “Arun does not likes apples” is grammatically incorrect in standard English. The correct sentence is “Arun does not like apples.” This error can be explained by examining the structure of English, particularly subject–verb agreement, auxiliary verbs, tense, and the formation of negative sentences. The sentence contains a subject, an auxiliary verb, a main verb, and an object. “Arun” is the subject, “does” is the auxiliary verb, “not” is the negative marker, “like” is the main verb, and “apples” is the object. Its basic structure can be represented as Subject + Auxiliary Verb + Negation + Main Verb + Object. The main grammatical problem occurs in the verb phrase “does not likes.” In the simple present tense, English uses the auxiliary verb “do” or its third-person singular form “does” to form negative sentences. When the subject is third-person singular, as in “Arun,” the auxiliary “does” carries the grammatical marking for the third-person singular. Therefore, the main verb must remain in its