I've set up the normal.dot file so that it has the styles I need for all word
documents.

My problem is this (for example):

When I work in a new document in word and decide to just change one word to
bold or left aligned (so it's slightly different to the style that is
selected) it also changes the attributes of all the text in that document
that has been based on that style.

How do I set up the document so there are specific styles set but there is
the flexibility to modify some text without changing any other text in that
document?

Thanks,
Helen