That's not right vs This ain't captain kangaroo

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

That's not right

Top 3,000 (common)

This ain't captain kangaroo

InformalBeyond 10,000 (less common)
Most formal: That's not rightMost common: That's not right
 That's not rightThis ain't captain kangaroo
Pronunciation🇬🇧 //ðæts nɒt raɪt//🇺🇸 //ðæts nɑt raɪt//🇬🇧 //ðɪs eɪnt ˈkæptɪn ˈkæŋɡəruː//🇺🇸 //ðɪs eɪnt ˈkæptɪn ˈkæŋɡəru//
MeaningThat is incorrect or unfair.This is not Captain Kangaroo.
ExampleWhen he claimed the project was successful, I thought to myself, 'That's not right.'When he said we could leave early, I thought, this ain't captain kangaroo!
RegisterNeutralInformal
How commonTop 3,000 (common)Beyond 10,000 (less common)
Collocationsthat's not right at all, that's not right to say, that's not right for you, that's not right in this situationthis ain't reality, this ain't fair, this ain't happening
Common mistakesUsing in a formal report or presentation where a softer expression is better., Misusing it in a context where clarification is needed instead of just saying it's wrong.Using 'ain't' in very formal writing., Confusing the expression with other references to TV characters., Assuming all audiences will understand the reference.
Usage notesUse this phrase to indicate disagreement or to highlight a mistake. It's neutral and suitable in most contexts. Avoid in overly formal situations.Used to express disbelief or disagreement, often in a casual context. Avoid in formal situations.

See it in real clips

That's not right
This ain't captain kangaroo

Frequently asked questions: That's not right vs This ain't captain kangaroo

What's the difference between That's not right and This ain't captain kangaroo?

That's not right: That is incorrect or unfair. This ain't captain kangaroo: This is not Captain Kangaroo.

Which is more formal: That's not right and This ain't captain kangaroo?

That's not right is the most formal of these.

Which is more common: That's not right and This ain't captain kangaroo?

That's not right is the most common in everyday English.

Can you show an example of each?

That's not right: When he claimed the project was successful, I thought to myself, 'That's not right.' This ain't captain kangaroo: When he said we could leave early, I thought, this ain't captain kangaroo!

Can I use That's not right and This ain't captain kangaroo interchangeably?

Not always. That's not right and This ain't captain kangaroo 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.

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