blow up
4 meanings
destroy something with a bomb, or be destroyed by one
What does "blow up" mean in this sense?
Examples
- The terrorists threatened to blow up the railway bridge.
- The old warehouse was blown up by the demolition team early this morning.
- They planted a device under the vehicle and blew it up before dawn.
How to use it
The basic transitive pattern, used when an agent deliberately destroys something with an explosive.
Soldiers blew up the pipeline to slow the enemy's advance.
Separation is strongly preferred with short noun objects and is the most natural word order in everyday use.
The engineers decided to blow the old bridge up rather than repair it.
When the object is a pronoun, it must go between the verb and the particle — this is not optional.
The fuel depot was a major target, so they blew it up just before midnight.
Used without an object when the thing that explodes is the subject of the sentence — no agent is mentioned.
The car blew up moments after the driver stepped away.
The passive form is very natural, especially in news writing, and the agent is often left out.
The railway line was blown up, causing major disruption to services across the region.
Common Collocations
Common Mistakes
When the object is a pronoun like 'it' or 'them', it must go between 'blow' and 'up'. Placing the pronoun after 'up' is always incorrect.
'Go off' describes a bomb or device exploding by itself, while 'blow up' can mean the same but is also used when someone deliberately causes the explosion. They often overlap, but only 'blow up' works naturally with a human agent causing the destruction.
It sounds unnatural to say someone 'is blowing up' a target as an ongoing action. Use the simple past, present, or a modal verb instead.
Usage
This phrasal verb is neutral in register and is used in both everyday speech and formal news writing. It also works intransitively when something explodes on its own: 'The car blew up' — no object needed in this pattern.
fill something with air, like a balloon or tyre
Sense 2: What does "blow sth up" mean?
Examples
- Can you help me blow up these balloons for the party?
- I blew up the air mattress with a foot pump before the guests arrived.
- The tyres need blowing up — they look a bit flat to me.
How to use it
The most common pattern, used when the object is a noun phrase. Both the separated and unseparated forms are natural.
We need to blow up the paddling pool before the kids can use it.
When the object is a pronoun, it must go between 'blow' and 'up' — never after 'up'.
Here are the balloons — can you blow them up while I set the table?
The separated form with a noun object is very natural in requests and instructions.
Could you blow the air mattress up before our guests arrive tonight?
The passive is natural when the focus is on the state of the object rather than who did the action.
All the inflatables had been blown up before the beach party started.
This pattern is useful for describing something that is flat and requires air.
The lilo needs blowing up — it was completely flat after the last trip.
Common Collocations
Common Mistakes
Learners sometimes forget the word 'up' and say 'blow the balloons', but this is unnatural in English. You must always include 'up' to get this meaning.
When you use a pronoun like 'it' or 'them', it must go between 'blow' and 'up', never after 'up'.
The inflation meaning only works with objects that hold air, like balloons, tyres, or inflatables. Using an object like a building or bridge will make listeners think of the explosion meaning instead.
Usage
This sense is neutral and used in both British and American English. It is the most common informal alternative to the more formal word 'inflate', and is the natural choice in everyday conversation.
make a photo or picture bigger
Sense 3: What does "blow sth up" mean?
Examples
- Could you blow up this photo so we can see the faces more clearly?
- The image was blown up to A2 size and displayed on the classroom wall.
- I blew the map up on the photocopier so it was easier to read.
How to use it
The most straightforward pattern: the image (photo, picture, map, etc.) follows the particle without separation.
Can you blow up the diagram so everyone in the room can see it?
With shorter noun phrases, the object very naturally sits between the verb and the particle — this is the most common spoken form.
She blew the portrait up and had it framed for the living room.
When replacing the object with a pronoun, it must go between the verb and the particle — never after 'up'.
I've got the screenshot — let me blow it up so we can read the text.
The passive is very natural, especially when the focus is on the image rather than the person doing the work — common in professional and print contexts.
The photograph was blown up to A1 size and displayed at the entrance to the gallery.
Adding a size reference makes the enlargement meaning completely clear and is a frequent pattern in design and print instructions.
Could you blow up this section of the map to A3 for the presentation?
Common Collocations
Common Mistakes
When using a pronoun as the object, it must go between 'blow' and 'up', not after 'up'. This is one of the most common errors with separable phrasal verbs.
Because 'blow up' has a well-known meaning related to explosions, learners sometimes worry about ambiguity. In practice, context almost always makes the enlargement sense clear — if the object is a photo, image, or map, native speakers will always understand the enlargement meaning.
'Zoom in' refers to magnifying something on screen in real time, while 'blow up' refers to producing an enlarged copy or version. Use 'blow up' when talking about printing or creating a larger version of an image.
Usage
This sense is neutral and works in both spoken and written English. It's especially common in photography, design, and print contexts. The noun form 'a blow-up' (an enlarged photo) is also used in everyday English.
suddenly get very angry and shout
Sense 4: What does "blow up" mean?
Examples
- My dad blew up when he found out I'd crashed the car.
- She rarely loses her temper, but she completely blew up at the meeting yesterday.
- If you tell him the project is delayed again, he's going to blow up.
How to use it
The most basic form — the verb stands alone with no object, simply describing someone losing their temper.
Everyone in the room went quiet when the director blew up.
Use 'at' followed by a person to show who the anger was directed towards.
She blew up at her flatmate over the mess in the kitchen.
Use 'over' or 'about' followed by a noun to indicate what triggered the anger.
He completely blew up over a minor scheduling change.
Intensifiers like 'really', 'completely', or 'just' are commonly placed before 'blow up' to emphasise how strongly someone reacted.
My manager really blew up when he saw the quarterly figures.
A clause beginning with 'when' or 'after' is often used to explain the moment or event that triggered the outburst.
She blew up when she found out the deadline had been moved again.
Common Collocations
Common Mistakes
In this sense, 'blow up' is intransitive — there is no direct object. Saying 'she blew him up' to mean she made him angry is incorrect and shifts the meaning entirely to the explosion sense.
Context is key: when 'blow up' describes anger, the subject is always a person reacting emotionally. If a physical object is involved or the sentence is transitive, the meaning is likely about an explosion, not anger.
'She is blowing up' sounds unnatural unless you are describing a scene happening right in front of you. When telling a story or describing habitual behaviour, the simple past or present simple is much more natural.
Usage
This phrasal verb is neutral to informal and works well in both spoken English and casual writing. It is common across both British and American English without significant regional difference.
Frequently Asked Questions
Does 'blow up' always mean to destroy something with a bomb?
No — 'blow up' has several different meanings in English. The key is context. If the sentence involves a bomb, explosive device, or a building or vehicle being destroyed, it has this meaning. But 'blow up' is also used to mean inflate something (like a balloon), enlarge a photo, or suddenly lose your temper. Look at the objects and the situation to work out which sense is being used.
Can 'blow up' be used in the passive?
Yes, and it's actually very common, especially in news articles and historical writing. You can say 'The bridge was blown up' without mentioning who did it. This passive form is natural and widely used.
Can something 'blow up' without anyone causing it — like an accident?
Yes. When 'blow up' is used without an object, the thing that explodes is the subject: 'The fuel tank blew up.' This pattern doesn't imply that anyone deliberately caused it — it simply describes the explosion. Both the deliberate and accidental uses are natural.
What kinds of things can you 'blow up' in this sense?
Typically large structures or vehicles — bridges, buildings, pipelines, cars, railway lines, power stations, and aircraft are all very common objects. The key is that the object should be something physically destructible and that the context suggests an explosion. Avoid using this phrasal verb with small everyday objects, as that would sound unnatural.
Does 'blow up' always mean inflate? I've heard it used in different ways.
'Blow up' has several different meanings in English, and this page covers only the inflation sense. The object is the key clue — if it's something that holds air (a balloon, tyre, or lilo), the inflation meaning is clear. A separate section on this page covers the other senses.
Can I use 'blown up' as an adjective?
Yes! 'Blown up' can be used as a compound adjective before a noun, with a hyphen: 'a blown-up balloon' or 'a fully blown-up air mattress'. This is a natural and common usage.
Is it natural to say 'blow up with a pump' or does it only mean using your mouth?
Both are completely natural. You can blow up a tyre or inflatable with a pump, a foot pump, an electric pump, or by mouth. Speakers often specify the method when it's relevant, for example: 'I blew up the mattress with a foot pump.'
Can I use 'blow up' in passive sentences?
Yes, the passive is very natural with this phrasal verb. It works especially well when you want to focus on the object rather than the person doing the action, for example: 'The beach balls had already been blown up by the time we arrived.'
Does 'blow up' always refer to photographs, or can I use it for other things?
It works with any flat visual image — photographs, pictures, maps, diagrams, screenshots, and similar items. What matters is that the object is something visual that can be reproduced at a larger size. You wouldn't use this sense with non-visual objects.
Can I use 'blow up' when talking about making something bigger on my phone or computer screen?
It can be used in digital contexts, but it usually implies creating a larger version of the image rather than temporarily zooming in. If you're pinching to zoom on a screen, 'zoom in' is more natural. If you're resizing and saving, or printing at a larger size, 'blow up' fits perfectly.
Is there a noun form of 'blow up' for an enlarged photo?
Yes — 'a blow-up' (often hyphenated) is a common noun that refers to an enlarged photograph or print. For example: 'They displayed a huge blow-up of the team photo on the wall.' It's used in everyday English, particularly in photography and design contexts.
Can I say 'I am blowing up the photo' using the present continuous?
It's grammatically possible but sounds a little unnatural in most situations. English speakers tend to use the simple present, past, or a modal form instead — for example, 'I'll blow up the photo' or 'Can you blow it up?' The present continuous is more natural for ongoing physical actions, and this sense usually refers to a single completed task.
How big does something need to be to say it was 'blown up'?
There's no fixed size — 'blow up' just means enlarged relative to the original. You can blow up a screenshot to fill a screen, or blow up a photo to poster size. It's often used with size references like 'to A3' or 'to poster size' to be more specific, but these aren't required.
Does 'blow up' always mean getting angry? It seems to have other meanings too.
No, 'blow up' has several different meanings depending on context. This particular sense — suddenly losing your temper — always involves a human subject reacting emotionally. A separate section on this page covers the other senses.
Can I use 'blow up' in formal writing, like a report or email?
It's better to avoid it in formal contexts. In professional or written English, phrases like 'lose one's temper' or 'react angrily' tend to sound more appropriate. 'Blow up' works well in conversation, storytelling, and casual writing.
Is it natural to say 'blow up at someone' or should I just say 'blow up'?
Both are natural. You can say 'she blew up' if the context already makes it clear who the anger was directed at, or add 'at + person' when you want to be specific about the target. Adding 'at someone' is very common and sounds completely natural in English.
Why is the past tense used so often with 'blow up'?
Because this phrasal verb most naturally describes a specific incident that already happened — a moment when someone suddenly lost control of their emotions. When people talk about arguments, conflicts, or dramatic moments, they usually recount them in the past tense.
Is there a difference between 'blow up over something' and 'blow up about something'?
Both are natural and interchangeable when describing the cause of someone's anger. For example, 'he blew up over a minor error' and 'he blew up about a minor error' mean the same thing. 'Over' is perhaps slightly more common, but both sound equally natural to native speakers.
Ready to practise?
Practise 1,000+ English phrasal verbs with interactive gap-fill exercises.
Start Practising →