In our discussion of ‘telegraphic speech’, we mentioned that in children’s early sentences the nouns and verbs often appear without the endings that adult speakers would use in those contexts:

drop blanket (You dropped the blanket.) kitty big (Those kitties are big.) Mummy chair (This is Mummy’s chair.)

Looking through the Corpus, you will have noticed that as children get older, as their vocabulary increases, and as their sentences become more complex, these endings start to appear. You will also have noticed the children producing words like putted. Putted is an error, but a very clever one as we shall see.