Presume vs. Assume

Posted: March 5th, 2014, 5:58 pm   By: brittany.corners

“‘Presume’? How you like I ‘presume’ to throw you in the river? You like that ‘presume’?”—Jon Voight, with his incomparable, Oscar-worthy Paraguayan accent in the glorious Anaconda

This week, we examine the difference between presume and assume.

Writers commonly encounter confusion when trying to decide between using presume or assume. Both verbs derive from the same Latin root sumere—which means “to take”—and the distinction between them is nuanced but important. Let’s look at their definitions:


1) to take something for granted, or to suppose something on the basis of probability or lack of evidence to the contrary

  • Ex) In a court of law, Ronald is presumed innocent until proven guilty—and even if he is found guilty, shouldn’t we laud his courage for expanding the common conception of recycling?

2) to take liberties or be bold enough to do something on a seemingly unwarranted basis

  • Ex) Don’t presume to tell this German party machine to be more careful with his car and the $50,000 worth of tools he left in the trunk. YOLO, bro.


1) to suppose something without proof

  • Ex) You might assume that a normal family with sane parents and vulnerable children would not want a wild, filthy crow flying around and crapping all over the house . . . but you’d be wrong.

2) to take something on, often responsibility or power

  • Ex) With its we-don’t-beat-around-the-bush-with-names special, My Giant Facial Tumor, TLC finally assumed control of the basic cable market for deformity-related television.

What’s the Difference?

Both words involve supposing something or taking something on, but the distinction between presume and assume boils down to degrees of certainty or audacity. Presume finds its basis in a strong proof or boldness that underlies the action being taken. Assume doesn’t operate with this level of nerve: in other words, assume doesn’t presume.