Its – it's so simple

If it’s any help it’s like this:
it’s is it is; its is its tail-bone
its hump, its halitosis, whatever it is,
that is. If it’s still not clear,
use its for what it possesses,
for instance, you’d say,
"If it’s on its way out and it’s snowing
it will grab its hat and coat."
It being, perhaps, a gnome.
You do understand that it, the it
we established above, is not snowing?
For it’s, think contraction,
the kind where vowels elide,
which is to say hide behind
that vital apostrophe mark
(its curly or straight incarnation).
It’s not that difficult, really, is it?