Is "clase" a singular, masculine noun?

Question

I'm having to learn the difference between using algún and ningún and alguno and ninguno. The rule is that you use algún and ningún before singular masculine nouns. The rule is that you use alguno and ninguno if the word after it is not a singular masculine noun and there is a period after it. Is the word, clase, a singular masculine noun? Which form do I use for the below sentence? Algún or Ningún or Alguno or Ninguno?

Hoy no tengo ________________ clase.

Answer 1

"clase" is feminine for which you seem to have no rule. I suggest that you get better rules.

Hoy no tengo ninguna clase. (you use ninguno/ningún/ninguna because the sentence is negative)

Ninguno changes to ningún before masculine, singular nouns (apocopation). Other than that it is a normal adjective. (except it precedes the noun as it is a quantifier, not a descriptive adjective)

Ninguno(s), ninguna(s) can also be a pronoun where apocopation has no application.

ninguno