Final answer:
The sentence 'Tiene mucho calor hoy.' is grammatically correct in Spanish.
Step-by-step explanation:
The sentence Tiene mucho calor hoy. is grammatically correct in Spanish. This sentence translates to 'It is very hot today.' In Spanish, the subject 'tiene' (third person singular) agrees with the noun 'calor' and the adjective 'mucho.' Additionally, the word 'hoy' indicates that the event is happening in the present. Hence, the sentence is grammatically correct.
Learn more about Spanish weather expressions