rule out

decide that something is not possible or not a choice

B2

What does "rule sth out" mean?

To rule something out means to decide that it is not possible or not worth considering. It describes a process of elimination — something was thought about and then rejected as an option or explanation. You will often hear it in news reports, medical situations, and investigations, where experts are narrowing down possibilities: a doctor might rule out a particular illness, or police might rule out a suspect. Importantly, negative constructions are just as common, and often more natural — phrases like 'can't rule out' or 'haven't ruled out' signal that a possibility is still being taken seriously. The phrase carries a slightly formal tone but is also perfectly natural in everyday conversation when someone is weighing up their options.

Examples

How to use it

rule out + possibility/option/idea

The most common pattern — used when formally or mentally eliminating something as a possibility.

The committee has ruled out a merger for the time being.

rule + pronoun + out

When the object is a pronoun, it must go between 'rule' and 'out' — this separation is not optional.

The timing seemed suspicious, but the police eventually ruled it out.

can't / won't / refuse to + rule out + object

Negative and modal constructions are extremely common and often more natural than the affirmative form.

Officials say they can't rule out further disruption to services.

be ruled out (passive)

The passive is very natural, especially in news and formal contexts, often with 'has been' or 'cannot be'.

A technical fault cannot be ruled out until the investigation is complete.

rule out + the possibility/chance + that-clause

When the ruled-out idea is explained in detail, a 'that'-clause is added after 'the possibility' or 'the chance'.

We can't rule out the possibility that the delay was caused by human error.

Common Collocations

the possibilitythe optionfoul playsurgerya suspectfurther action

Common Mistakes

Pronoun placement

When the object is a pronoun like 'it' or 'them', it must go between 'rule' and 'out'. Placing the pronoun after 'out' is incorrect in English.

✗ We can't rule out it.
✓ We can't rule it out.
Confusing 'rule out' with 'count out'

'Count out' is informal and typically used to exclude a person from participating ('count me out'). 'Rule out' is broader and more formal, used when eliminating possibilities, options, causes, or scenarios — not just people.

✗ You can count out a heart attack — the test results were clear.
✓ You can rule out a heart attack — the test results were clear.
Separating with a long noun phrase

When the object is a long or complex phrase, keep 'rule out' together rather than splitting it. Separation works well with short objects but sounds awkward with lengthy ones.

✗ They ruled the possibility that it was caused by a software glitch out.
✓ They ruled out the possibility that it was caused by a software glitch.

Usage

Very common in news, medical, and investigative contexts. Negative constructions are especially frequent — 'can't rule out' and 'haven't ruled out' are often more natural than the affirmative form.

Frequently Asked Questions

Does 'rule out' always mean something is definitely impossible?

Not necessarily — it means something has been eliminated from consideration based on current evidence or reasoning, but that judgment can sometimes change. In fact, constructions like 'can't rule out' are very common precisely because the speaker wants to signal that something is still a live possibility. The phrase implies a deliberate decision to set something aside, rather than a permanent, absolute fact.

Is 'rule out' only used in formal or professional contexts like news and medicine?

It's most frequent in those contexts, but it's also natural in everyday conversation. You might say 'I'm not ruling out a career change' or 'Let's rule out the cheap option first' without sounding overly formal. It's a versatile phrase that works across a wide range of situations.

Can 'rule out' be used in the passive form?

Yes — the passive is actually very common with this phrasal verb, especially in news and official language. Phrases like 'has been ruled out' and 'cannot be ruled out' appear frequently in reports and press statements. For example: 'Sabotage has not been ruled out by investigators.'

What kinds of things can be 'ruled out'?

The object is usually an abstract possibility, cause, or option — such as 'the possibility', 'foul play', 'surgery', 'a suspect', 'terrorism', or 'further action'. You can also use pronouns ('rule it out') or vague words like 'anything' and 'nothing'. It's less commonly used with physical, countable objects — you wouldn't 'rule out a chair', for example.

Can I use 'will be ruling out' to talk about the future?

This construction sounds unnatural with 'rule out'. To talk about future elimination of possibilities, it's better to use 'will rule out', 'won't rule out', or 'is not going to rule out'. For example: 'The team won't rule out signing a new player in January' sounds much more natural than 'The team will be ruling out...'

Ready to practise?

Practise 1,000+ English phrasal verbs with interactive gap-fill exercises.

Start Practising →