assume

Assume and presume have very similar meanings—they both mean to suppose that something is true without being able to confirm it. Assume, however, usually implies that the conclusion reached by the person doing the assuming is not based on much. Presume, on the other hand, often implies that the conclusion is based on something a bit stronger, such as some evidence or past situations in which the same thing happened.

For example, you might presume that someone will be attending a meeting because they always attend and you have no reason to think they won’t be there. The word assume could also be used in this scenario, but it’s most likely to be used in situations in which there was less of a reason to have come to a certain conclusion. For example, you might assume something about someone you’ve just met based only on how they look (which is never a good idea).

A good way to remember this difference in how the two words are used is that the prefix pre- in presume means “before”—when you presume things, you’re often basing that presumption on something that has happened before. As for assume, well, we’ll just assume you know a good way of remembering how it’s used.

Assume and presume also have a few meanings that don’t overlap. Assume can mean to take on, adopt, or be endowed with something, as in I don’t want to assume any new responsibilities. Presume can mean to undertake or do something without permission or justification, as in I don’t presume to speak for the entire class.

Here are examples of assume and presume used correctly in a sentence.

Example: I assumed you knew what you were doing when you volunteered to bake the cake, but apparently I shouldn’t have.

Example: I presumed, based on your resume, that you knew how to work with this software.

Want to learn more? Read the full breakdown of the difference between assume and presume.

Is assume or presume the better choice in the following sentence?

We don’t know anything, so we shouldn’t _____ anything.