British spellings and American spellings

• aeroplane [UK] - airplane, aero plane [US]
  
• analyse, analyze [UK] - analyze [US]
  
• analysed, analyzed [UK] - analyzed [US]
  
• behaviour [UK] - behavior [US]
  
• catalogue [UK] - catalog [US]
  
• categorise, categorize [UK] - categorize [US]
  
• categorisation, categorization [UK] - categorization [US]
  
• categorised, categorized [UK] - categorized [US]
  
• centre [UK] - center [US]
  
• cheque [UK] - check [US]
  
• colour [UK] - color [US]
  
• doughnut [UK] - donut [US]
  
• earnt, earned [UK] - earned [US]
  
• equalling [UK] - equaling [US]
  
• favour [UK] - favor [US]
  
• grey [UK] - gray [US]
  
• hiccough, hiccup [UK] - hiccup [US]
  
• labour [UK] - labor [US]
  
• license (verb), licence (noun) [UK] - license [US]
  
• manoeuvre [UK] - maneuver [US]
  
• metre [UK] - meter [US]
  
• neighbour [UK] - neighbor [US]
  
• programme [UK] - program [US]
  
• pyjamas [UK] - pajamas [US]
  
• practise (verb), practice (noun) [UK] - practice [US]
  
• recognise, recognize [UK] - recognize [US]
  
• specialised, specialized [UK] - specialized [US]
  
• specialising, specializing [UK] - specializing [US]
  
• standardise, standardize [UK] - standardize [US]
  
• standardised, standardized [UK] - standardized [US]
  
• tyres [UK] - tires [US]
  
• travelled [UK] - traveled [US]
  
• travelling [UK] - traveling [US]