Skip to main content
to put a spanner in

to put a spanner in

8.6
To cause a plan to fail or have big problems
  • idiom
  • /pʊt ə ˈspænə ɪn/
  • UK
translation icon : estropear
  • The sudden rainstorm put a spanner in our outdoor event preparations.

Examples

  • The last-minute change in requirements put a spanner in the development process.

  • Don't put a spanner in the works again!

  • If you cancel now, it will really put a spanner in everyone's plans.

  • The unexpected rain put a spanner in our picnic plans.

  • If you change the dates of the meeting, you'll put a spanner in our plans.

  • His unexpected resignation put a spanner in the project's timeline.

  • Don't ask for more resources now; it will just put a spanner in the works.

Synonyms

to turn (something) upside down
vsto put a spanner in
  • Informal
51 4.5

Cause a big sudden change that leaves people confused

is narrower, focusing on complications in plans rather than broad transformation
to rock the boat
vsto put a spanner in
  • Informal
20 5.3

Do or say something that causes trouble and upsets other people

focuses on plan or process disruption rather than social disturbance
to open a can of worms
vsto put a spanner in
  • Informal
3 7.4

Create a difficult situation with many unexpected problems

is immediate disruption to a plan rather than long unfolding complexity
to throw a wrench in
vsto put a spanner in
  • US
2 8.0

Cause a problem that stops a plan or activity

is the same idea expressed with a different idiom
to throw a monkey wrench into the works
vsto put a spanner in
  • Informal
1 8.6

Cause problems on purpose that stop a plan or process from working smoothly

is similar but may be accidental or less deliberate
to overset someone's plans
vsto put a spanner in
7.7

To ruin someone's plans by making them fail or change suddenly

targets general process disruption rather than personal plan failure
to stir up drama
vsto put a spanner in
  • Informal
7.0

To cause trouble between people to get attention

is about practical plan complications rather than emotional provocation

Antonyms

1.0

Give help to a person or idea

to facilitate
  • Formal
187 4.9

To make a task or process easier and help it happen

How Disruptive

to ruin
2.0
to sabotage
164 7.1
to derail
64 4.6
to put a spanner in
  • UK
8.6
to disrupt
269 4.4
to interfere
487 3.5

Surface Forms

put a spanner in infinitive
put a spanner in past participle
putting a spanner in present participle
puts a spanner in third person singular

Morphology

put + a + spanner + in

The sense 'to cause disruption' is metaphorically related to literally inserting a spanner into machinery so it jams, so a learner who imagines that physical scenario could infer the meaning. However, this is a culturally specific metaphorical idiom (often fixed as 'put a spanner in the works') and requires world knowledge and figurative interpretation, so it is not fully predictable from the parts alone.

Etymology

The expression put a spanner in may come from the image of someone dropping a spanner, a metal wrench, into the moving parts of a machine to make it stop. So, put a spanner in now means 'to cause a problem' or 'spoil a plan'.