People can burn things, or things can burn in a fire, or fires can burn. "After you read this message, please burn it." "I watched the logs burning for several hours." "The fire burned for several hours." If you "ignite" something, you add the spark that makes it start burning. People can ignite things or things can ignite. "I ignited the fire."=I started the fire "After I prepared a pile of tinder and kindling, I ignited it." "The spark caused the pile of gunpowder to ignite." "Inflame" is almost always used metaphorically, for love and similar emotions or hate and similar emotions. "Jill's dress inflamed Bob's desire." "The nation's new policies further inflamed the hatred of its enemies."

They aren't that similar! Lol Ignite: to catch fire, or to begin to burn (the boy scout ignited a fire without using a match) ps: it is also used in space rocket launches, re: when the engine starts. Burn: to be on fire. "The candle burned for one hour." Inflame: This has nothing to do with fire, at least in modern uses. It means to make something more extreme (I tried to tell my boyfriend to slow down our relationship, but his love for me became even more inflamed) or, when describing a physical symptom, to make something look red or look infected(I scratched the insect bite so much that it became inflamed)