representation of input text in a conversation

[John Anderson]

These are two of the standard solutions.  The third is

(goal-three
     sentence s1
     response nil)

(a1
     word     who
     parent   s1
     position first)

(a2
     word     are 
     parent   s1
     position second)

(a3  
     word     you
     parent   s1
     position third)

I would argue that the data on serial memory are most consistent with this.