Assume Versus Presume
It is easy to misuse words, and slang doesn’t help. Colloquialisms aside, when you are writing or editing, it is important to understand the rules, even when you intend to break them. So, what’s the proper way to use ASSUME versus PRESUME? Let’s find out…
The simplest answer is this:
ASSUME (a verb meaning “to suppose“): is when you believe something is possible or true based on NO EVIDENCE.
So, this is a belief based on nothing.
PRESUME (a verb meaning “to suppose“): is when you believe something is possible or true based on SOME EVIDENCE OF PROBABILITY though it might not actually be correct.
And, this is a belief based on the likelihood, such as a repeat behavior or outcome.
“Assume and presume both mean “to take something for granted” or “to take something as true.” The difference between the words lies in the degree of confidence held by the speaker or writer.
https://www.merriam-webster.com/words-at-play/assume-vs-presume