There are some differences between British and American usage in spelling. So many words ending in -bre, -tre in Britain ( metre, fi bre) are spelled -er in the US (meter, fi ber). Words ending in -our in Britain (colour, labour) are usually spelled -or in the US (color, labor). Most verbs ending in -ize or -ise are spelled -ize in the US with the exception of a small number of verbs like advertise, devise, surprise having different origin. The words ending in -ce or -se are spelled in American use -se: defense, offense, while in British use they are spelled defence, offence. In British use, words of more than one syllable ending in -l and forming derivative double the l before a vowel: travel – travelling – travelled, cancel – cancelling – cancelled. In American use it is not doubled: travel – traveling – traveled, etc.The American spelling is in some respects simpler than its British variant, in other respect just different. The table below illustrates some of the other differences.

                                                                       

Words  with spelling:	British English	American  English
-re/ -er	centre,  theatre	center,  theater
-ou-/-o-	favourite	favorite
-gue/ -g	dialogue,  catologue	dialog,  catalog
-ce/ -se	defence,  offence	defense,  offense
-our/ -or	honour,  colour	color,  honor
-ise/ -ize    -yse/ -yze	realize,    analyse	realize    analyze
-ll-/ -l-	jewellery	jewelry
-ae-/ -e-	encyclopaedia	encyclopedia
-xion/-ction	refl  exion	refl  ection
-ity/ -ty	speciality	specialty
-s-/-z-	cosy	cozy

There is a tendency of simplifying the spelling of some words: plough, programme, judgement they are British and plow, judgment, program for American.