The distinction between "realize" and " realise " rests solely in their spelling. This difference stems from variations in American and British English. Both words convey identical meanings and are used interchangeably, depending on the regional language preference. What to Know Realize and realise are alternate spellings of the same word. In the US and Canada, realize is by far the more common spelling. In the UK, Australia, and New Zealand realise dominates, though realize is sometimes used too. The discrepancy stems from a history of different dictionaries and publishers choosing their preferred versions until a pattern stuck. Realize and realise both mean to become aware of something or to achieve something. The difference lies in the spelling based on regional variations. Realize is the preferred spelling in American English, while realise is used in British English. For example, you might read in an American publication, “He realized the importance of punctuality.” Conversely, a British writer might say, “She realised she had left her keys at home.” When writing, choose the spelling that matches the ... What’s the difference between realise and realize? Can you use the words interchangeably or is one a misspelling? Learn the difference in this guide.