When referring to an extreme example for comparison, English seems to have just one word, even:
Even an idiot could do it.
But Spanish seems to have three:
I had always used aun for this but then realized it wasn't the only possibility, such as in the old Shakira song, Octavo Día:
Hasta un ciego lo puede ver (Even a blind man could see it)
Does the choice of which to use depend on grammar or nuance, or is it purely up to the speaker's preference?