The correct spelling of the plural form of "anything" is "anythings" /ˈɛniθɪŋz/. It is important to note that "anything" is an uncountable noun, meaning it cannot be used in plural form without a countable noun that qualifies it, such as "anythings you want to buy." Using "any things" instead is a common mistake as it separates the two words and changes the meaning. When in doubt, use a dictionary or grammar guide for clarification on spelling and usage.