—A drinking-cup is a cup for drinking.
A copy-book is a book for copying.
SERIES D
(Direction and source of motion)
—Turn from the right to the left. (da ... a, a ... da)
Turn from the left to the right.
—Draw a line from the bottom of the paper to the top.
Draw a line from the top of the paper to the bottom.
—Go from your seat to the cabinet.
Go from the cabinet to your seat.
—Change the pen from your right hand to your left hand.
Change the pen from your left hand to your right hand.
Permutations
The child has built the first sentences on each of the slips with his cards, and he has reproduced the others by changing simply the preposition cards. In this way he has seen how the position of objects relative to each other is determined wholly and only by the use of the preposition. The preposition, therefore, determines the relation of words, the relation of a noun to some other word, here to another noun or to a verb. In the phrase,
Set one chair opposite another chair,
if we take away the preposition, leaving,
Set one chair another chair,