Failed vs That didn't work out

When to use each in English, with meaning, register, and examples.

Failed

Top 1,000 (very common)B2adjective

That didn't work out

Top 2,000 (common)
Most common: Failed
 FailedThat didn't work out
Pronunciation🇬🇧 /["/feɪld/"]/🇺🇸 /["/feɪld/"]/🇬🇧 //ðæt ˈdɪdnt wɜːk aʊt//🇺🇸 //ðæt ˈdɪdnt wɜrk aʊt//
Meaningnot successfulIt didn’t succeed or have a good result.
Examplea failed writerAfter months of effort, that didn't work out for the team.
RegisterNeutralNeutral
How commonTop 1,000 (very common)Top 2,000 (common)
CEFR levelB2-
Part of speechadjective
Collocationsfailed attempt, failed experiment, failed project, failed to meet, failed gradeswork out a plan, work out issues, work out details
Antonymssucceeded, achieved, triumphed-
Common mistakesConfusing 'failed' with 'fail' (incorrect verb tense), Using 'failed' with the wrong object (e.g., 'failed the test' instead of 'failed in the test'), Overusing it in informal contexts where lighter terms would be more appropriateUsing 'out' incorrectly - 'work' and 'out' are part of the phrase., Confused with 'work it out,' which means to solve a problem., Misusing in positive contexts - it's specifically for failures.
Usage notesUse 'failed' to describe attempts that did not succeed. It's neutral and can be used in various contexts, from academic to casual conversations.Used to express that a plan or idea failed. Appropriate in both casual and formal settings. Avoid in very formal documents.

See it in real clips

Failed
That didn't work out

Frequently asked questions: Failed vs That didn't work out

What's the difference between Failed and That didn't work out?

Failed: not successful That didn't work out: It didn’t succeed or have a good result.

Which is more common: Failed and That didn't work out?

Failed is the most common in everyday English.

Can you show an example of each?

Failed: a failed writer That didn't work out: After months of effort, that didn't work out for the team.

Can I use Failed and That didn't work out interchangeably?

Not always. Failed and That didn't work out are related and overlap in some contexts, but they differ in register, how common they are, and usage, so swapping one for another can change the meaning or tone. Check the differences above before substituting.