why the englsh lunguege litters are big and littel?

Answer 1

1. Purpose of capitalisation
The reasons are:
a) to show the beginning of a sentence;
b) to indicate a name or proper noun;
http://en.wikipedia.org/wiki/Proper_noun
c) to indicate languages (nouns) and nationalities (adjectives), thus he is an Algerian national, and he speaks Arabic; and
c) for the first person singular "I".

2. Language family
a) English is partly derived from Anglo-Saxon, a Germanic language.
http://en.wikipedia.org/wiki/Germanic_languages
b) In German even common nouns have a capital letter. "In the German orthography, nouns and most words with the syntactical function of nouns are capitalised, which is supposed to make it easier for readers to find out what function a word has within the sentence."
http://en.wikipedia.org/wiki/German_language