Explanation: Here’s why: Subject-Verb Agreement: The subject "He" is a third-person singular pronoun. Grammatical Structure: In the present simple tense, for third-person singular subjects (he, she, it), verbs typically take an "-s" ending. Correct Form of the Verb: "Goes" is the correct form of the verb "to go" to use with the third-person singular subject "He" in the present simple tense. Therefore, the correct sentence is: "He goes to the gym on Mondays."

Explanation: Here’s why: Subject-Verb Agreement: The subject "They" is a plural pronoun. Grammatical Structure: In the present simple tense, verbs used with plural subjects (like "They") do not take an "-s" or "-es" ending. Correct Form of the Verb: "Have" is the base form of the verb used with plural subjects in the present simple tense. Therefore, the correct sentence is: "They have lunch at noon."

Explanation: Here’s why: Subject-Verb Agreement: The subject "The dog" is a singular noun. Grammatical Structure: In the present simple tense, for third-person singular subjects (he, she, it, or in this case, "The dog"), verbs typically take an "-s" ending. Correct Form of the Verb: "Barks" is the correct form of the verb "to bark" to use with the third-person singular subject "The dog" in the present simple tense. Therefore, the correct sentence is: "The dog barks every night."

Explanation: Here’s why: Subject-Verb Agreement: The subject "My brother" is a singular noun. Grammatical Structure: In the present simple tense, for third-person singular subjects (he, she, it, or singular nouns like "My brother"), verbs typically take an "-s" ending. Correct Form of the Verb: "Lives" is the correct form of the verb "to live" to use with the third-person singular subject "My brother" in the present simple tense. Therefore, the correct sentence is: "My brother lives in London."

Explanation: Here’s why: Subject-Verb Agreement: The subject "I" is a first-person singular pronoun. Grammatical Structure: In the present simple tense, verbs used with first-person singular subjects (like "I") use the base form of the verb. Correct Form of the Verb: "Do" is the correct base form of the verb "to do" to use with the first-person singular subject "I" in the present simple tense. Therefore, the correct sentence is: "I do my homework after dinner."

Explanation: Here’s why: Subject-Verb Agreement: The subject "We" is a first-person plural pronoun. Grammatical Structure: In the present simple tense, verbs used with plural subjects (like "We") do not take an "-s" or "-es" ending. Correct Form of the Verb: "Clean" is the base form of the verb "to clean," which is used with plural subjects in the present simple tense. Therefore, the correct sentence is: "We clean the house every weekend."