“Aging” and “ageing” are established regional spellings. Cambridge labels aging as US and ageing as UK, so the choice should follow the intended variety or house style.
ReviewedEvidence2 sourcesSectionEnglish Usage
Quick answer
Use “aging” in US English and “ageing” in UK English when referring to getting older.
Key details
Confusion Familyregional-spelling
Noun Variant ScopeCambridge identifies aging as US spelling and ageing as UK spelling in the getting-older sense.
Rule Familyregional-orthography
Termsaging, ageing
Further guidance
Core difference
“Aging” is the standard US spelling and “ageing” is the standard UK spelling in the getting-older sense.
Fast Test
Choose the form that matches the intended regional or house style.
Variant Boundary
Both forms are established; do not mark a documented regional form wrong merely because another variety prefers the alternative.
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.
“Analyze” is the standard US spelling and “analyse” is the standard UK spelling of the same verb. The distinction is regional spelling; use the form that matches the target variety or editorial style.
“Behavior” is the US spelling and “behaviour” is the UK spelling. Use the form consistent with the regional variety or editorial style of the document.
Both “canceled” and “cancelled” are standard past-tense spellings of “cancel”; US English usually uses one l, while UK English normally uses two. Cambridge records the -ll- forms and notes that US English usually uses -l-, so the difference should be presented as a regional preference rather than a correctness split.
“Catalog” is the standard US spelling and “catalogue” is the standard UK spelling for the corresponding noun and verb. The distinction is primarily regional spelling; retain the form required by the intended variety or established name.
