Quantifiers indicate quantity. Some examples of quantifiers include: all, some, many, few, and no. Quantifiers are also dependent of a noun. It is important to acknowledge that quantifiers only indicate a vague quantity of objects, not a specific number, such as twelve, dozen, first, single, or once, which would be considered numerals.
This is a companion discussion topic for the original entry at http://grammarerror.com/tags/quantifier