Collocations for assertion - noun

bold, confident, proud | categorical, dogmatic, general, sweeping
sweeping assertions about the role of women in society

simple
The argument needs to progress beyond the simple assertion that criminals are made not born.

unfounded, unsubstantiated, unsupported

make
How can you make such an assertion?

justify, prove, support
Your assertion is not supported by the facts.

accept, agree with | challenge, question
Researchers have recently challenged these assertions.

reject | refute

~ about
assertions about human nature