Knock-knock jokes. Every child learns to laugh or groan at Knock-knock jokes like this one (from the vast collection at www.scatty.comjokesknock): Who's there Abyssinia! Abyssinia who? Abyssinia when I get back!
Truly awful, we agree, but kids love them. Why? Because they play with the very loose connection between pronunciation and grammatical structure. This one builds on the important phonetic fact that we run words into one another, so "I'll be seeing you" does indeed sound pretty similar to "Abyssinia". To make fun in class out of Knock-knock jokes you could ask for one where the two meanings need pronunciations that are not just similar, but identical. Then you could discuss whether the spelling system would be better if it was tied more closely to pronunciation (eg, if "Bacon" was spelt the same as "baking")?
Newspaper headlines. Another kind of grammatical ambiguity often pops up in newspaper headlines, like some of the collection at www.putlearningfirst.comlanguage06sentenambiguity.html
Juvenile Court to Try Shooting Defendant
The grammar point here is that "shooting" is meant to modify "defendant", but it could equally well be the complement of "try", with "defendant" as its object. But not all ambiguities are grammatical; here's another one from the same list whose ambiguity lies in the two meanings of "arms": Iraqi Head Seeks Arms A useful classroom exercise would take a list of such headlines and decide for each one whether the ambiguity lay in the sentence structure or in the meanings of individual words. This would be time well spent because KS3 writers have to learn to spot ambiguities in their own writing.
Nonsense. The CarrollLear school of poetry is pure grammatical fun for children: Twas brillig, and the slithy toves Did gyre and gimble in the wabe. Jabberwocky is a very obvious way into grammatical structure, with its sharp contrast between nonsense nouns, adjectives and main verbs (the "big" meaning-bearing words), and conventional conjunctions, prepositions, determiners and auxiliary verbs (the "little" grammar-bearing ones). Why not let the class produce its own nonsense verse (maybe one word per pupil) and see for themselves how much easier it is with big words than with little ones?
Richard Hudson is professor of linguistics at University College, London Geoff Barton is headteacher of King Edward VI School, Bury St Edmunds, Suffolk