Dear Jack,
What is the difference between a swordfish and a sailfish?       
-- Joshua

Dear Joshua,
Well, they’re related in that they belong to the same order, but the two are in different families of classification (the next, more specific level below “order”). The primary difference is that swordfish have more of a “sword” on their noses and sailfish have more of a “sail” (dorsal fin) on their backs!
-- Jungle Jack