Main Difference – Assume vs Presume
Assume and presume are two words that are commonly used interchangeably in English since both these verbs mean ‘to suppose’. However, there is a distinct difference between assume and presume. This difference lies in the degree of certainty of the supposition. Assume is used when there is no or little proof to make a guess. But presume can be used when we make an informed guess based on probability or reasonable evidence. This is the main difference between assume and presume.
Assume – Meaning and Usage
Assume is a verb that refers to the action of supposing something to be the case without any proof. Assume comes from Latin assumere. Assumption is the noun form of assume and assumption is a guess we make without any proof and evidence. When we assume something, we have no prior experience, no knowledge of the situation; we just make a guess. So there is a good chance that our assumption will be proved to be incorrect.
We can’t just assume that he is the thief; we need proof.
He had no experience in teaching, so he assumed that the students will obey him.
I assume that you are single.
We assumed that he was telling the truth.
Assume also have some other meanings. It can also give out the meaning ‘to take on’ or ‘begin to have’
He assumed the responsibility of the company.
She assumed to a fake name and disappeared from the country.
I just assumed it.
Presume – Meaning and Usage
Presume also means ‘to suppose’ or ‘to take something for granted as true’. But the difference between assume and presume is that presume typically involves some sort of evidence. In other words, we presume something based on the available evidence, prior experience, knowledge of the situation or on the basis of probability. Thus, presume is ‘to make an informed guess, based on available evidence’. The noun form of presume is presumption.
For example, think about the law, which states that defendant is innocent, until proven guilty. Here, we presume that the defendant is innocent until it is proven that he is guilty. The examples below will help you to understand the meaning of presume better.
I presumed him to be David, judging from the photos Ella has sent.
The police presumed that the killer had entered the house through a broken window.
The spokesperson stated that the missing soldiers are presumed to be dead.
After a long day at school, I presume you are tried.
Presume is also used to describe taking an attitude. The Oxford dictionary defines this meaning as ‘arrogant or impertinent enough to do something’. For example,
I do not presume to know enough about their family to interfere in their family matters.
She had presumed too great a level of familiarity.
Difference Between Assume and Presume
Definition
Assume is ‘to suppose without proof’
Presume is to ‘make an important guess based on available proof’
Evidence
Assume involves no evidence.
Presume involves evidence.
Accuracy
Assumptions are less likely to come true.
Presumptions are less likely to come true. 
