What's the plural form of phlogiston theory? Here's the word you're looking for.
Answer
The noun phlogiston theory can be countable or uncountable.
In more general, commonly used, contexts, the plural form will also be phlogiston theory.
However, in more specific contexts, the plural form can also be phlogiston theories e.g. in reference to various types of phlogiston theories
or a collection of phlogiston theories.
