The standard expression is “one and the same,” meaning the same person or thing. “One in the same” is a common reinterpretation, but it is not the standard form in edited English.
ReviewedEvidence2 sourcesSectionPhrases & Idioms
Quick answer
Use “one and the same”: “The founder and CEO are one and the same person.”
Key details
Canonical Formone and the same
Common Errorone in the same
Core Meaningthe same person or thing
Variants
one and the same
Dictionary-listed form.
one in the same
Common reinterpretation; not the standard edited form.
Further guidance
Correct Form
Cambridge lists “one and the same” as the idiom. Grammarist identifies “one in the same” as a common nonstandard reinterpretation.
History Boundary
This guide does not assert an independently verified first printed occurrence.
Meaning
The phrase emphasizes that two descriptions or identities refer to a single person or thing.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
The established expression is “bad rap,” referring to severe criticism, an unfavorable judgment, or an unfair accusation depending on context. “Bad wrap” is not the standard spelling of that expression; “wrap” has its own unrelated meanings.
The established expression is “with bated breath,” used for waiting in an anxious or excited way. Cambridge records “bated” in this fixed phrase. “Baited breath” is a sound-based spelling confusion, not the form supported by the reviewed dictionary evidence.
The established expression is “at someone’s beck and call,” meaning ready and willing to do whatever that person asks. “Beckon call” is a common mishearing or eggcorn, not the standard form of the idiom.
“Champing at the bit” and “chomping at the bit” are both used for being very eager or impatient to begin. Cambridge explicitly records champing/chomping as variants; “champing” reflects the older horse-related wording, while “chomping” is a widely accepted modern variant.
“Couldn’t care less” means not caring at all and is the clearest form across English varieties. Cambridge also records “could care less” as a US informal variant used with the same intended meaning, despite its literal wording appearing logically opposite.
The established adjective is “deep-seated,” meaning strongly rooted, firmly established, or difficult to change. “Deep-seeded” is a common reinterpretation when this meaning is intended, even though a literal seeded construction can occur in unrelated contexts.
The standard expression is “dog-eat-dog,” describing a situation in which people compete ruthlessly for their own advantage. “Doggy-dog” is a sound-based reinterpretation, not the standard form of the expression.
The established expression is “get away scot-free” or “escape scot-free,” meaning to avoid punishment or a penalty. “Scotch-free” is not the standard form; the word is “scot,” historically connected with a tax or payment.
