- Have you ever wondered if you should “make” or “do” an assumption?
- Do you want to know which adjectives describe an assumption that is probably wrong?
- Are you looking for the right prepositions to use after the word “assumption” in a professional report?
Mastering collocations—words that naturally hang out together—is the secret to moving from “textbook English” to sounding like a fluent, native speaker. For the word assumption, using the right verb or adjective can change your tone from hesitant to confident. This guide will help you use this high-frequency noun accurately in academic, business, and daily life contexts.
Essential Collocations using ASSUMPTION as a Noun
The word “assumption” is almost exclusively used as a noun in modern English (the related verb is “assume”). In linguistic terms, it refers to something that you accept as true or as certain to happen, even without proof. Here is how to use it effectively.
Common Verbs Used with Assumption
In English, we don’t just “have” assumptions; we interact with them. These are the most frequent verb pairings used in 2024.
- Make an assumption: To believe something is true without checking the facts.
Example: “It is dangerous to make assumptions about a client’s budget before the first meeting.” - Challenge an assumption: To question whether something is actually true.
Example: “The new data challenges the assumption that younger users prefer video over text.” - Base something on an assumption: To use a belief as the foundation for a plan.
Example: “The entire marketing strategy was based on the assumption that interest rates would drop.” - Test an assumption: To perform an experiment or check facts to see if a belief is right.
Example: “We need to run a pilot program to test our assumptions about user behavior.” - Confirm an assumption: To prove that a belief was correct.
Example: “The survey results confirmed my assumption that most employees prefer a hybrid work model.”
Adjectives Often Paired with Assumption
Adjectives help you describe the quality or the danger of the assumption being made.
- A safe assumption: Something that is very likely to be true.
Example: “It is a safe assumption that the office will be closed on Christmas Day.” - A mistaken/flawed assumption: An idea that is based on wrong information.
Example: “The project failed because it was built on flawed assumptions.” - An underlying assumption: A hidden belief that influences how someone thinks.
Example: “We need to look at the underlying assumptions in this economic theory.” - A common assumption: Something that many people believe.
Example: “There is a common assumption that all introverts are shy, but that isn’t always true.” - An implicit assumption: An assumption that is suggested but not clearly stated.
Example: “There is an implicit assumption in this contract that the work will be done by June.”
Prepositional Phrases with Assumption
Prepositions are often the hardest part for ESL learners. Here are the two most common structures.
- Under the assumption (that): Acting while believing something is true.
Example: “I bought the tickets under the assumption that you were coming with me.” - Working on the assumption (that): Planning or doing work based on a specific belief.
Example: “We are working on the assumption that the budget will be approved next week.”
The Master Summary Table
| Collocation | Part of Speech | Quick Meaning |
|---|---|---|
| Make an assumption | Verb + Noun | To decide something is true without proof. |
| Challenge an assumption | Verb + Noun | To doubt or question a belief. |
| Safe assumption | Adjective + Noun | A belief that is likely correct. |
| Flawed assumption | Adjective + Noun | An incorrect or logicaly weak belief. |
| Under the assumption | Prepositional Phrase | While believing that… |
| Deeply held assumption | Adverb + Adj + Noun | A very strong, fundamental belief. |
Common Mistakes: Natural vs Unnatural
Learners often translate directly from their native language, leading to “collocation errors.” Here is how to fix them.
| Do Not Say | Say This |
|---|---|
| Take an assumption | Make an assumption |
| An assumption is broken | An assumption is challenged or disproven |
| In the assumption that… | On the assumption that… or Under the assumption that… |
| A wrong assumption (Too basic) | A mistaken or flawed assumption |
“When we started the startup, we were working on the assumption that customers wanted more features. However, after three months, we had to challenge that underlying assumption. It turned out to be a mistaken assumption; users actually wanted a simpler interface. We quickly made the assumption that a redesign would help, and thankfully, our latest data confirmed that assumption.”
Frequently Asked Questions about Assumption Collocations
Is it “on the assumption” or “under the assumption”?
Both are correct and commonly used in 2024. “Under the assumption” is often used when describing the reason for an action (e.g., “I acted under the assumption…”). “On the assumption” is more common in formal logic or project planning (e.g., “The plan is based on the assumption…”).
What is the difference between an assumption and a presumption?
In modern English, an “assumption” is often based on little to no evidence. A “presumption” is a bit stronger—it is an idea you accept as true because it is logical or probable, though not 100% certain. In daily conversation, “assumption” is much more common.
Can I say “I assume” instead of “I make an assumption”?
Yes. In fact, using the verb “assume” is often more natural in casual speech. “I’m making an assumption” sounds more deliberate or formal, often used when you are analyzing your own thinking process.
What is a “flawed assumption”?
A “flawed assumption” is a collocation used specifically in business and science to describe a starting idea that is logically broken or based on bad data. It is a more professional way to say “a wrong idea.”
How do I use “assumption” in a sentence about the future?
You can use the phrase “Proceeding on the assumption.” For example: “We are proceeding on the assumption that the weather will be clear for the outdoor event.”
I'm still learning, but this article gives me confidence to use 'assumption' more correctly. Thanks for the clear examples!
Can you give more examples of sentences where using the wrong verb with 'assumption' would sound really awkward? I'm trying to train my ear for what sounds 'off'.
That's an excellent way to train your ear, Guo! For instance, saying 'He *did* an assumption about her motives' sounds very awkward and incorrect. Or 'They *got* an assumption that the project would fail' – instead of 'They *held* an assumption' or 'They *made* an assumption.' The more you read and listen to authentic English, the more natural the correct collocations will become!
This is perfect for my B1/B2 students. It addresses a very common error and provides practical examples. I also appreciate the reminder that 'assumption' is almost exclusively a noun.
Glad to hear it, David! Understanding the grammatical category (noun vs. verb) of a word like 'assumption' is fundamental, especially when introducing collocations. We aim for clarity that benefits learners across different proficiency levels.
This blog always has the best explanations for things I never even thought about. Thank you for making my English sound more natural!
The article highlights common verbs. What about less formal contexts? Would someone ever 'jump to an assumption' or is 'jump to a conclusion' the only idiomatic usage there?
That's a great observation, Lena! While 'jump to a conclusion' is the standard idiom, you wouldn't typically 'jump to an assumption.' An assumption is usually something you 'make' or 'hold,' whereas a conclusion is something you 'reach' or 'jump to' (often hastily). It's a good reminder that even closely related words have distinct collocations!
I wonder if the origin of 'make an assumption' has something to do with 'making' a mental construction? Fascinating how language evolves!
Excellent post! I'll be using this as a quick reference for my students writing academic papers. The emphasis on 'make an assumption' being more common than 'do' is crucial.
Thank you, Clara! We're glad you find it valuable for academic writing. Precision in collocations, especially with high-frequency nouns like 'assumption,' significantly enhances the professionalism and clarity of written work.
In Japanese, we often use a verb that's closer to 'hold' or 'grasp' an idea. So 'make an assumption' feels a bit active to me. But I understand now why it's used. Good explanation!
It's fascinating how different languages conceptualize similar actions, Kenji! Your observation about 'hold' or 'grasp' is very insightful. While 'make' is indeed active, it suggests the mental construction of that belief. Thanks for sharing your perspective!
Could you give more examples of adjectives for assumptions that are likely wrong? Besides 'unwarranted' or 'false,' are there others that convey a subtle nuance of being ill-founded or hasty?
Absolutely, Priya! Beyond 'unwarranted' and 'false,' you could also use:
* **Hasty assumption:** made too quickly without enough thought.
* **Flawed assumption:** containing errors or weaknesses.
* **Presumptuous assumption:** showing overconfidence or arrogance.
* **Dubious assumption:** of doubtful quality or validity.
These add different shades to how an assumption is perceived!
I found the part about prepositions particularly helpful. I always mix up 'assumption *about*' and 'assumption *that*.' Your examples make it clear. Thanks!