please tell me what to do in order to prevent the first letter of the word on
each line from capitalizing after i hit the spacebar .
Stop hitting Enter at the end of every line. Seriously. A word processor is not
a typewriter; it will automatically go to the next line as it needs to.
What you're seeing is the AutoCorrect option to capitalize the first word of
each _sentence_. When you hit Enter, you're telling Word that you're starting a
new paragraph, and the start of a new paragraph is implicitly the start of a new
sentence, too.
You can turn off the option by going to Tools > AutoCorrect Options >
AutoCorrect and unchecking "Capitalize first letter of sentences". Judging by
your capitalization-free post, though, you really need it turned on. Only e e
cummings could get away with that kind of rule-breaking.