In 1958, Jean Berko Gleason invented The Wug Test. She wanted to test whether kids understand abstract patterns in language. The test involved showing kids pictures and giving them names for the images they were seeing.
So let’s do The Wug Test.
What’s a Wug, you ask?
OK so that’s a Wug. What about if there are two of them? Then what do we have?
Did you get it? There are two WUGS!
A Wug isn’t a real thing, so (unless you’ve heard of The Wug Test) you won’t have heard the word said before, and you won’t know the plural from experience. You just know the structures of English grammar. You know on a subconscious level (even if you’ve never thought about it) that in English we generally show pluralisation of nouns by adding the sound ‘s’ or ‘z’, depending on the final sound in the singular form.
At the Pre-Wug Stage, kids can produce plurals for words they’ve heard before, but not for made-up words like Wug. At a particular point in their linguistic development, once they’ve gained enough experience of linguistic patterns, kids become able to apply these patterns to new words which enter their vocabulary - even words which are placed there artificially by tricksy linguists. Like Wug.
The Wug test starts off easy with the word Wug, and then gets progressively harder. Usually we pluralise nouns by adding ‘s’ or ‘z’, but with sometimes we add an extra vowel sound in to make the word easier to say. We do this with words ending in ‘ch’, ‘sh’, ‘s’ and ‘z’, so that we get ‘matches’, ‘shoelaces’ and ‘roses’. Sooo…
That’s RIGHT, there are two GUTCHES!
As the test gets even harder, we move on to verb conjugation.
Most people assume that RICK is a regular verb and that yesterday he RICKED. But some people occasionally go for the irregular form RACK, possibly taking the pattern from verbs line ‘swim’ which becomes ‘swam’ in the past tense.
Other questions ask kids to create adjectives from nouns:
’This dog is covered in quirks? What kind of dog is he? He is a QUIRKY dog!’
…or to create compound nouns:
’This is a Wug. This is the place the Wug lives. It is a WUGHOUSE.’
…or to signal possession:
’This is a Wug. This hat belongs to the Wug. It is the WUG’S hat.’
Perhaps the hardest questions are those which ask the kid to signal possession of plurals:
’These are two Wugs, and these are their hats. They are the WUGS’ hats.’
(…the Wugses hats?!)
My personal favourite is this one:
’This is a Wug. This is a tiny Wug. It is a WUGLING / WUGLET / WUGEEN (?)’
Of course The Wug Test isn’t an intelligence test, and shouldn’t be treated as one. Although I don’t think there’s any harm in showering a kid with praise if they get it right! It signals a kid’s developmental stage, and their willingness to play along - some kids don’t get the logic of the game, and I think that’s fair enough. They might be unwilling to accept that a Wug is a thing just because you tell them that it is. They might speculate creatively about all the different things the man might have done yesterday. They might just not think that this is a fun game. All are acceptable responses. If your kid doesn’t get it, it’s not a reason to panic - I’ve tested lots of my friends, many of them highly-skilled professional adults, and not all of them gave the expected answers.
The Wug Test provides evidence that kids don’t learn grammatical patterns by simply copying the people around them. If they did then they would only be able to tell you the plural of Wug or the past tense of Rick if they had heard these words used before. The fact that kids (sometimes) get it right at quite a young age shows that they are able to extrapolate regular grammatical patterns even with a relatively short period of linguistic experience.
Also it’s fun.
Long live the Wug!
To hear The Wug Test in action, listen to Accentricity episode 4: Learning to Talk.