Title
The central irony of the book develops from its title. Although it is to be expected simply as a result of generic expectations of plotting, the fact that the students ultimately turn out not to be unteachable is the irony driving the plot.
The Title, Part Deux
The title is also connotatively ironic. Unteachable is commonly understood to refer to someone who cannot be taught, but that is fundamentally impossible. Anyone can be taught since there is nothing in the definition of “teach” suggesting that a requirement that what is taught must also be learned. A student cannot actually be unteachable since the student is only capable of learning that information which has been successfully conveyed. If something is unteachable then by definition the reference is to the process of instruction and not the person who fails to learn it. (Technically, the correct term that is applicable here would seem to be “The Unlearnables” but that just doesn’t sound quite right.) This is a case where the connotation of the word has superseded its logical definition. The irony here is that the story still works either way: the students have proven they not unteachable in connotative sense while Mr. Kermit has proven that they are not unteachable through successful instructional methods.
Vuvuzelas
Irony also comes in layers relative to the vuvuzelas. Mr. Kermit hates these noisemakers with a passion but ironically defends the right of his students to not be excluded from enjoying them. Ultimately, the irony grows even more robust as the vuvuzelas become the instruments through which students honor him rather than—as he feels is usually the case—torturing him.
Reputation
Mr. Kermit proves himself the most capable teacher at school by proving that they can be successfully taught (as well as they are not incapable of learning.) As indicated, this is the driving irony of the story, of course, but once again there is another level. In proving that “unteachable” applies in neither sense of the word, he also challenges the irony of his reputation as being a bad teacher who should have been dismissed years before and is absolutely undeserving of his pension.
Scandal
The reason that Mr. Kermit’s reputation has suffered—and, as a result, the education system which has suffered as a result of his losing his passion for teaching—is the most tragic ironic element of the book. Kermit’s entire life has spiraled downward ever since his tangential involvement in a cheating scandal in which he was not actively involved and did nothing wrong.