What Does “Foul sth up” Mean?
“Foul sth up” means to make a mistake or spoil something, often causing a problem or failure.
Introduction
The phrase foul sth up is a common informal phrasal verb used in English to describe situations where someone messes up or ruins something. It can refer to making errors in work, plans, or any activity that leads to a negative result. Understanding the foul sth up meaning helps English learners express frustration or explain when things go wrong. This phrase is often used in everyday conversations, especially when talking about mistakes that could have been avoided. Knowing how and when to use “foul sth up” will improve your speaking and writing skills by allowing you to describe problems clearly and naturally.
Quick Info Box
- Phrasal verb: foul something up
- Type: transitive
- Level: B2 (Upper-Intermediate)
- Short meaning: to make a mistake or spoil something
Structure (Grammar Rules)
“Foul sth up” is a separable phrasal verb. This means you can place the object (something) between “foul” and “up” or after “up.”
- Correct: I fouled the report up.
- Also correct: I fouled up the report.
Both forms are acceptable, but placing the object between the verb and particle is more common in spoken English.
How to Use “Foul sth up”?
Use “foul sth up” when you want to say that someone has made a mistake or caused a problem with something. It is informal and often expresses mild frustration or disappointment.
Examples of use include describing errors at work, problems in plans, or messing up simple tasks. It always requires an object — what exactly was fouled up.
Examples
- He really fouled up the presentation by forgetting his notes.
- Don’t foul up the schedule; we have little time to finish.
- She fouled the order up by sending the wrong items.
- We fouled up the project because we didn’t communicate well.
- Try not to foul it up this time — it’s very important.
Common Mistakes
- Incorrect: I fouled up.
- Correct: I fouled it up. (Needs an object)
- Incorrect: She fouled up the.
- Correct: She fouled up the plan.
Remember, “foul sth up” is transitive, so you must include what was fouled up.
Differences / Synonyms
Similar phrasal verbs include:
- Muck up: Also informal, means to make a mistake or spoil something. Very similar to “foul up.”
- Screw up: More casual, means to mess something up badly.
- Mess up: A general phrase for making mistakes or causing disorder.
“Foul up” often sounds slightly more formal than “screw up” or “muck up” but less formal than “mess up.”
Common Collocations
- foul up the plan
- foul up the schedule
- foul up the order
- foul up the project
- foul up the report
Real-life Dialogue
Anna: Did you finish the report for the meeting?
Tom: I tried, but I think I fouled it up. I mixed some of the data.
Anna: Oh no! Can you fix it before the meeting?
Tom: I’ll do my best. I don’t want to foul it up again.
Practice
Fill in the blank with the correct form of “foul up”:
- He __________ the schedule by arriving late.
- Be careful not to __________ the order.
- We __________ the report, so we had to rewrite it.
- She always __________ things when she’s nervous.
FAQs
- Q: Is “foul up” formal or informal?
A: It is informal and used mostly in casual conversations.
- Q: Can I say “foul up” without an object?
A: Usually, you need an object, but in some cases, “foul up” is used without one to mean “make a mistake.”
- Q: What is the difference between “foul up” and “mess up”?
A: Both mean to make a mistake, but “mess up” is more general and common.
- Q: Can I use “foul up” in writing?
A: It’s better for informal writing, such as emails or chats.
- Q: Is “foul up” used in British or American English?
A: It is used in both but is more common in British English.

