Is There a Difference?

Those keen on their pet pedantries love to claim there is a difference in meaning between pairs of words. Sometimes they're right (can you tell forgo from forego?), but sometimes... Is there a difference between:

among/amongst
country/countryside
different from/to
due to/owing to/because of
each/every
faith/belief
feeling/emotion
hanged/hung
homogenous, homogeneous
in/within
instinctive, instinctual
judgement/judgment (everyday use/legal use)
learnt/learned
older/elder
oldest/eldest
on either side/on each side
sceptic/skeptic
single and double quotes
skeptic/sceptic
title/entitle
triple/treble
truth/Truth
unreasoning/irrational
upon/on
which/what
while/whilst
within, in