When do you use apostrophe for plural?

Apostrophes are generally not used to form plurals; they are primarily used for indicating possession or contractions. However, apostrophes can be used in some cases to clarify the plural of letters, numbers, or symbols, such as "Mind your p's and q's" or "There are two 7's in the address." In these instances, the apostrophe helps avoid confusion. In standard pluralization of nouns, simply adding an "s" or "es" is sufficient.