BRITISH  ENGLISH  -  AMERICAN  ENGLISH   
some differences :
 

                  Verbs ending in -'ize' or '-ise'

                  In Britain, some verbs end in either -ize or -ise.  Both are used.
                  In America, they always end in -ize.

                     examples :              apologise/apologize
                                                   organise/organize
                                                   realise/realize

                  Regular - Irregular forms

                  Some verbs have alternative regular and irregular past tense and
                  past participle forms, for example : dream - dreamed or dreamt.

                  In Britain, the irregular form is more often used, whereas in
                  American English, there is a preference for the regular form.

                  Here are some of those verbs :

                                           dream       dreamed/dreamt
                                           learn         learned/learnt
                                           spell         spelled/spelt
                                           spoil         spoiled/spoilt
            
                  and also:
                                           dive - dived - dived (GB)   
                                           dive -  dove - dived (US only)
 

  The Pronoun
       'one'

 

                   Americans do not often use 'one' to mean "people in general",
                   nor do they use 'one's' or 'oneself'.

                   GB :     One should look after one's health.
                   US :     You should look after your health.
                               People should look after their health.

  DATES

 

                   There are differences in the way dates are said and written.

                   GB :     4th July - the fourth of July
                   US :     July 4   -  July four - July fourth

                   GB :     6/12/99 means the 6th of December 1999
                   US :     6/12/99 means the 12th of June 1999

                   The British use 'and'  between  hundred and the rest of the number.
                   The Americans leave it out.

                   GB :     Two hundred and twenty.
                   US :     Two hundred twenty.