Both are guesses. Assume is weaker (little or no evidence), presume is stronger (reasonable evidence). But how to remember which is which?
- Assume = make a guess based on little or no evidence.
- Presume = make an informed guess based on reasonable evidence.
- When you ass-ume something, it's just a guess that you have pulled from your ass.
- When you pre-sume something, you have some pre-knowledge or pre-information to support your guess.
I suppose I should add a third word to the comparison: suppose. Coming soon™.
- The word definitions: Are 'Assume' and 'Presume' Synonyms? on Merriam-Webster
- The mnemonics: I pulled them from my ass.