Would it be Sports are an essential part to every high school or would it be Sports is?
Is it more than one sport? If so, "are" is correct. "Is" is singular. "He is..." "They are..."
Sports are -- high schools usually have several sports.
Note that "sports" is not usually capitalized unless it's at the beginning of a sentence or part of an official name, like "ABC Sports".
The correct phrase would be "Sports are an essential part of every high school."
The reason for using "are" instead of "is" is that "sports" is a plural noun, so it requires a plural verb. In English grammar, when the subject of a sentence is plural, the corresponding verb should also be plural.
To determine whether the verb should be singular or plural, you can identify the subject of the sentence. In this case, the subject is "sports," which is plural. Therefore, you should use the plural form of the verb, which is "are."
To ensure that your sentence is grammatically correct, it's always helpful to identify the subject and verb and make sure they agree in number. So, in this case, "sports" (plural subject) and "are" (plural verb) agree with each other.