Grammar
Style guide 
One space between sentences?
In the days of typewriters we used double spaces between sentences. But styles change. The Australian Commonwealth Style Manual: For Authors, Editors and Printers (2002) says:
"In typewritten (as distinct from typeset) material, it was customary to place two spaces after a colon, semicolon, full stop or other sentence-closing punctuation. Programs for word processing and desktop publishing offer more sophisticated, variable spacing, so this practice of double spacing is now avoided because it can create distracting gaps on a page."
It is a hard habit to break. If you wish to change to single spaces, I suggest you do a 'search and replace' at the end until you have retrained your fingers.
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