capitalizing the first word of a sentence seems like a dumb grammatical rule. one knows a word is the beginning of a sentence because it is following a punctuation mark. the capital letter is unnecessary.
the purpose of most rules in grammar is to make a sentence or paragraph more easy to read and to limit confusion.
edit: my mother brought up a possible purpose for capitalizing the first word of a paragraph. it does distinguish between punctuation marks used for things such as an abbreviation and punctuation that symbolizes the end of a thought. for example: "Meet me on Burnside St. before dark." capitalizing the beginnings of sentences does prevent one from thinking that "before dark" is a new sentence. while i'm talking about abbreviations, why in the hell is "abbreviation", which means shortening a word, such a long word?
