build up

slowly increase or grow stronger over time

B1

What does "build (sth) up" mean?

Build up describes something growing, increasing, or getting stronger over a period of time — either because someone is working at it deliberately or because it happens naturally as a process. You can use it to talk about developing positive things, like confidence, strength, or a business, but also about things that accumulate on their own, like pressure, stress, or traffic. The key idea is that the change is gradual and progressive, not sudden. It works both with an object ('She built up her savings') and without one ('Tension was building up'). There is also a very common noun form — 'a build-up' — which you will often see in phrases like 'a build-up of traffic' or 'the build-up to the final'.

Examples

How to use it

subject + build up + noun

The most common transitive pattern — someone deliberately increases or develops something over time.

He spent years building up a strong reputation in the industry.

subject + build + noun + up

With short noun objects, the particle can move to the end — both positions are natural.

She decided to build her savings up before looking for a new place to live.

subject + build + pronoun + up

When using a pronoun instead of a noun, the pronoun must go between the verb and 'up' — it cannot come after.

Your stamina is low right now, but you can build it up with regular exercise.

subject + build up (no object)

Used without an object when something accumulates on its own as a natural process.

Stress can build up quickly if you never take time to relax.

noun + be + built up + over/through + time phrase

The passive form is natural and common, especially when describing something developed or accumulated over a long period.

The brand was built up over many years through careful marketing and good customer service.

Common Collocations

build up confidencebuild up tensionbuild up strengthbuild up a reputationbuild up pressurebuild up debt

Common Mistakes

Pronoun placement

When you use a pronoun object, it must go between 'build' and 'up'. Placing it after 'up' is not correct in English.

✗ You need to build up it gradually.
✓ You need to build it up gradually.
Confusing 'build up' with 'pile up'

'Pile up' suggests things accumulating in a messy or out-of-control way, while 'build up' suggests something more gradual and often more deliberate. Choose based on whether the process feels controlled or chaotic.

✗ Work was building up on her desk and she felt totally overwhelmed.
✓ Work was piling up on her desk and she felt totally overwhelmed.
Adding 'to' by mistake

'Build up to' is a different sense meaning to gradually approach a big event or moment. If you just mean something is increasing or strengthening, do not add 'to'.

✗ He built up to his confidence before the presentation.
✓ He built up his confidence before the presentation.

Usage

Neutral and versatile — equally natural in conversation, business, and writing. The noun form 'build-up' is also very common (e.g. 'a build-up of traffic', 'the build-up to the final').

Frequently Asked Questions

Does 'build up' always involve someone doing something on purpose?

No — 'build up' can describe both deliberate action and natural processes. You can build up your strength on purpose, but pressure or tension can build up on its own without anyone intending it. The key idea is simply that the increase happens gradually over time.

Can 'build up' be used for negative things, like debt or stress?

Yes, absolutely. 'Build up' is very commonly used for things that grow in an unwanted or concerning way, such as debt, stress, pressure, or resentment. The word itself is neutral — the context tells you whether the accumulation is positive or negative.

What is the difference between 'build up' the verb and 'build-up' the noun?

'Build up' (two words, verb) describes the action or process of something increasing. 'Build-up' (hyphenated, noun) names the result — the accumulated amount or the period of growing activity. For example: 'Traffic builds up in the evenings' (verb) versus 'There's a build-up of traffic on the motorway' (noun).

Can I use 'build up' in the passive?

Yes, the passive is natural and quite common with 'build up', especially when talking about something that was developed or accumulated over a long period of time. For example: 'The company was built up from nothing by one determined person.'

What kinds of things commonly 'build up'?

The most common collocations include abstract things like tension, pressure, confidence, trust, momentum, and stress, as well as more concrete things like strength, muscles, a business, a collection, debt, and wealth. If something can grow gradually over time, 'build up' is likely to fit.

Related Phrasal Verbs

pile up

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