Final answer:
The sentence "Mi hermano podrá ir a la escuela mañana" is grammatically correct.
Step-by-step explanation:
The sentence "Mi hermano podrá ir a la escuela mañana" is grammatically correct.
The subject of the sentence is "Mi hermano", which means "my brother" in English.
The verb "podrá" means "will be able to", and the phrase "ir a la escuela" means "go to school". The adverb "mañana" means "tomorrow".
Learn more about Spanish grammar