In natural language, a predicate can be seen as the result of removing n names from a sentence, leaving gaps which can be filled by other names to make other sentences.
- In English, 'is a goat' is a monadic (unary) predicate. Applying it to the name 'Billy' yields the sentence 'Billy is a goat.'
- Similarly, 'kicks' is a dyadic (binary) predicate. Applying it to the names 'Aristotle' and 'Billy' yields the sentence 'Aristotle kicks Billy.'
- In the formula Fa AND NOTRba the letter F is a monadic predicate symbol and R is a dyadic one.