Twain uses irony in many points during this novel, by having his characters speak words (or, in Huck's case, think things) which are the opposite of the message he is trying to send. For example, in chapter five Huck's father says, "And looky here - you drop that school, you hear? I'll learn people to bring up a boy to put on airs over his own father and let on to be better'n what he is. You lemme catch you fooling around that school again, you hear? Now looky here; you stop that putting on frills. I won't have it. I'll lay for you, my smarty, and if I catch you about that school I'll tan you good." In this excerpt, the father is saying that schooling and education are not necessarily, and that they merely mean that a person is "putting on airs." Twain is sending the message that although Huck has a free spirit that should not constantly be confined to organized societies like schools, and should be able to roam free, it is not bad that he is attending school and learning to read and write .
Many other ironies have to do with slavery and racism. For example, in chapter six, Huck's father is telling him his views on America's government, and begins to criticize a state that permits free blacks. The character says: "There was a free ni there, from Ohio, a mulatter, most as white as a man .And what do you think? They say he was a p'fessor in a college And that ain't the wust. They said he could vote, when he was at home. Well, that let me out. Thinks I, what is this country a-coming to? They call that a govment that can't sell a free ni till he's been in the State six months ." This is an example of irony, because Twain, throughout the novel, gives a clear message that slavery is wrong, and yet has this character speak racist, insulting comments that are clearly pro-slavery. .
Another example of irony is in chapter five, chapter sixteen, when Huck begins to feel that he did wrong in helping Jim become a free man.
