Z

Verbs ending in -ize, -ise, -yze, and -yse

Many verbs that end in -ize can also end in -ise in British English. For example, in British English, all of the following spellings are acceptable: finalize/finalise; organize/organise; realize/realise. In American Englishthe only correct spellings are finalize, organize, and realize.  

In both American and British English, there is a small set of verbs that must always be spelled with -ise at the end. The main reason for this is that, in these words, -ise is part of a longer word element rather than being a separate ending in its own right. For example: -cise (meaning 'cutting) in the word excise; -prise (meaning 'taking') as in surprise; or -mise (meaning 'sending') in promise.

advertisecompromiseexerciserevise
advisedespiseimprovisesupervise
apprisedeviseincisesurmise
chastisedisguiseprise (meaning ‘open’)surprise
compriseexcisepromisetelevise

 

There are also a few verbs which always end in -yse in British English.

analysecatalyseelectrolyseparalyse
breathalysedialysehydrolysepsychoanalyse

 

In American English, they are all spelled with the ending -yze

analyzecatalyzeelectrolyzeparalyze
breathalyzedialyzehydrolyzepsychoanalyze


You can read more about the use of ‘ize’ and ‘ise’ on the Oxford Dictionaries blog. Here you will find more information about the historical usage of ‘ize’ and ‘ise’ and the difference between the two in the context of British English and American English.

 

Back to spelling.

You may also be interested in

Words containing the letter q

Spelling rules and tips

Common misspellings

See more from Endings beginning with vowels