Use 'presuppose' when you believe something before it's confirmed; it shows a level of certainty. He presupposes he'll ace the test, without seeing the results.
Pro Tip 2/3
Unverified Expectation
'Presuppose' implies an expectation not yet proven; it can reflect optimism or bias. She presupposes the weather will stay fine for the picnic.
Pro Tip 3/3
Precondition Thought
In planning, 'presuppose' shows assumptions made beforehand that guide actions. Our strategy presupposes a favorable market environment.