How To Teach A/An
The explanation that “an” is followed by a vowel is well known. However, this is often misunderstood because “an” actually comes before a vowel sound rather than a written vowel (that is, letter). This leads to examples like “He’s an honest man” and “There’s a university just across the street” (not “a honest man” or “an university”). The first example also illustrates something else that students sometimes find confusing, that “a” or “an” goes with whatever word comes next rather than always being affected by the noun, as in “an imposing woman” but “a woman”.
Some native speakers use “an” with words with a pronounced “h” as in “an historic day”, but this is neither consistent nor standard usage and so best ignored unless students bring it up.
If we ignore the “an historian” problem (as I always would at the level that “a”/“an” is usually presented) we basically have a simple distinction, with two tricky little points (silent H and U with a /ju:/ sound) to keep students on their toes. This means that practice is much more important than presentation, and in fact it is possible to do whole lessons with just a couple of minutes of actual grammar presentation, and this can be cut down still further if you make sure you use lots of realistic classroom language with “a” and “an” such as “Can I have a/an…, please?” and “What’s this? It’s an elephant” in the weeks before this point comes up in the book. The more elaborate presentation ideas below are therefore for higher-level classes.
Presentation activities for a/an
A/An chain stories
Make up or adapt at least two texts so that they have many examples of “a” and “an”, giving each student just one text each. They try to memorise the story and then tell it to someone else. Perhaps after people orally passing on the stories further times, students who have just heard the same story work together to write it down. They then compare their version with the original, commenting on factual and grammatical differences between the two versions and then trying to work out the difference between “a” and “an”.
This is like a teacher-led version of the game above. The teacher reads out a text with lots of examples of “a” and “an” twice. Students just listen the first time and listen and make notes the second time, then work together to reconstruct the whole text. Perhaps after comparing with the original text, students then discuss the rule for “a”/“an”.
A jigsaw story
Create or adapt a story so that it has lots of examples of “a” and “an” in it, then split it up after some of those words, e.g. “It was a” “dark and stormy night. An” “undertaker was working in the morgue and…”. Students put together the story from a combination of meaning and grammar, then discuss what the rules are for “a” and “an”.
A clap, a clap and another clap
This is slight variation on a well-known game where students sitting in a circle take turns brainstorming, the next person having to add to the list after three claps (i.e. on the fourth beat) after the person sitting next to them. This can be done with vocabulary and/or grammatical categories such as “Clothes with an” or “Words beginning with U”. Another possibility is for students to work their way through the alphabet in order, e.g. clap clap clap “An apple” clap clap clap “A bed”. For more intensive practice of “an” they could do the same thing with just A E I O U or in more advanced classes with the vowel sounds that the teacher has written on the board such as /a:/.
You can give “It’s a” or “It’s an” as the first clue for Hangman (preferably also continuing to give hints like “It’s usually black” and “It’s in my bag now” whenever they guess a letter that isn’t part of the word).
This is based on the old card game Snap!, with the match that someone should say “snap!” to being two cards that take “a” or two cards that take “an”. This obviously leads to more matches than most versions of this game, so you might want to add some completely blank cards that don’t match with anything to slow the game down.
This is also based on a popular card game, this time the memory game Pairs, where students find two face-down cards that match in some way. In this case a match is two cards that take “a” or two cards that take “an”. To add the target language, they should make a sentence describing the first card that they turn over (e.g. “It’s an orang-utan”) before they turn over the second one.