I got this confusion with a particular English grammar: when to say an independence. Like: as children mature, they develop an independence. (Actually...I don't think "an" is even necessary for "independence" when we say "a sense of independence.")
Other times, it's doesn't sound right to use "an". Like: we fought for independence.
My book explains that "an independence" refers to a continuously changing state in that sentence. But in the second one, independence is a concrete state.
Can someone explain how "an independence" is a continuously changing state and more importantly when to use "an"?