Learn Spanish (Latin America): No encuentro ningún sacacorchos en la cocina. - I cannot find any corkscrew in the kitchen.

Sacacorchos is a compound noun made from the verb sacar (to pull out) and the plural noun corchos (corks). In Spanish, compound nouns formed with a verb and a noun almost always use the plural form of the noun, so they end in s even when referring to a single item.

Since sacacorchos already ends in s, how do I make it plural?

The noun itself doesn't change form. You indicate whether it is singular or plural by changing the articles or adjectives around it. For example, el sacacorchos is singular, and los sacacorchos is plural. In this sentence, the singular adjective ningún tells us it is just one corkscrew.

Why use ningún here instead of ninguno?

The word ninguno drops its final o and gains an accent mark whenever it comes directly before a masculine singular noun. Because sacacorchos is grammatically a masculine singular noun in this context, it triggers this rule.

Isn't using No and ningún a double negative?