List I

idea or ideal?	Bristolians have particular difficulty distinguishing between these two because of the intrusive Bristol ‘l’. These exemplar sentences should help: Your IDEA is brilliant. This is an IDEAL spot for a picnic. His IDEALS prevent him from eating meat.
indexes or indices?	Both are acceptable plural forms of ‘index’ but they are used differently. Use INDEXES to refer to alphabetical lists of references in books. Use INDICES in mathematical, economic and technical contexts.
inter-/intra-	The prefix INTER- means between or among (e.g. international). The prefix INTRA- means within, on the inside (e.g. intravenous).
-ise or -ize?	Most words ending with this suffix can be spelt -ise or -ize in British English. American English is more prescriptive and insists on -ize whenever there is a choice. House-styles in Britain vary from publisher to publisher and from newspaper to newspaper. (You may have noticed that in this book I favour -ise.) When making your choice, bear these two points in mind: " These nineteen words have to be -ise: advertise, advise, apprise, arise, chastise, circumcise, comprise, compromise, despise, devise, disguise, enfranchise, excise, exercise, improvise, revise, supervise, surprise, televise. " Only one verb of more than one syllable has to be -ize: capsize. (One syllabled verbs like ‘seize’ still need care, of course.) Whatever you decide, be consistent within one piece of writing and be consistent with derivatives. If you use ‘realize’ in one paragraph, you must use ‘realization’ and not ‘realisation’ at another point in the same piece. If you use ‘sympathize’, then you must refer to ‘sympathizers’ and not to ‘sympathisers’ elsewhere. Many authorities prefer to use -ize when there is a choice. In practice, many writers prefer to use -ise because this choice is relatively trouble-free. The decision is yours!