“Realize” and “realise” are regional spelling variants of the same verb. Cambridge notes the UK “realise” form; which spelling to publish depends on the regional or house style being followed, not on a difference in meaning.
ReviewedEvidence1 sourceSectionEnglish Usage
Quick answer
Both spellings represent the same verb; choose “realize” or “realise” according to the intended regional or house style.
Key details
Confusion Familyregional-variant
Rule Familyregional-spelling
Termsrealize, realise
Further guidance
Core difference
The forms differ by spelling convention rather than core meaning.
Usage Boundary
Follow one regional or organizational style consistently; do not claim that the alternative spelling changes the verb’s meaning.
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.
“Apologize” and “apologise” are regional spelling variants of the same verb. Cambridge marks “apologise” as the usual UK form, so the practical choice is to follow the regional or house style required by the audience.
“Authorize” and “authorise” are regional spelling variants of the same verb. Dictionary guidance recognizes both, with “authorise” associated especially with British usage, so consistency with the intended regional or house style is the key choice.
“Capitalize” and “capitalise” are regional spelling variants of the same verb. Cambridge records the British “capitalise” variant, so writers should choose the form that matches their regional or publication style and use it consistently.
“Specter” and “spectre” are regional spellings of the same noun rather than words with different meanings. Cambridge identifies specter as the US spelling of spectre, so consistency with regional style is the main choice.
