English has many rules on capitalization and spelling, and spelling tends to vary between different dialects (especially British English and American English).

Capitalization in English

There are several times when letters must be capitalized in English. They are:
1) At the start of a sentence; "The cat is on the bed."
2) The first letter of a proper noun (a month/day/country/language/name etc.) and adjectives, adverbs etc. derived from them; "Peter went to Spain on Tuesday." and "John ate a Spanish dish."
3) In a religious context, when using 'he' to refer to God; "He thought it good."
4) First person singular: “I”.

Spelling in English

British English and American English have different ways of spelling certain words, especially those with ou in the middle, for example:
1. British English: colour, American English: color. 2. British English: honour, American English: honor.

Another variation is the use of 'z' instead of 's' in certain words in American English. 1. British English: capitalisation, American English: capitalization 2. British English: modernisation, American English: modernization. 3. British English: industrialisation, American English: industrialization. This usually only applies to words that end in -ise and -isation.