> Even more oddly, the double-negative (un & in) has no impact on its meaning "not flammable." But in- is not necessarily negative, it's also a prefix that can

> Even more oddly, the double-negative (un & in) has no impact on its meaning "not flammable." But in- is not necessarily negative, it's also a prefix that can mean "in" (like indoors, ingrown): inflammable means it "can be in flames". Actually, French makes it more obvious, as the verb for setting aflame is "enflammer" where "en-" is clearly the prefix that means "in", not the prefix that means "not". At least English uses two different prefixes for "uninflammable", even if there's some confusion possible. French has it as "ininflammable", with two "in-" prefixes that mean different things.