Twelve sentences with the adverb already picked out in bold and three columns to choose between: how, when, or where. A kitten stretches lazily on the rug, a parade starts soon, a cat hides upstairs, the store opens daily at nine.
Handing the child the adverb is deliberate. Sorting is a separate skill from spotting, and when the two are mixed a child who missed the adverb never gets to practice the sorting at all. Four of the twelve fall into each of the three categories, so a child who guesses one column all the way down gets a third of them right and no more, which is low enough that guessing shows.