4. Tony is 18 months old and around 5 pm when his father usually comes home, he looks at his mother and asks “Dada?”? His mother knows that Tony is asking if his dad is coming home soon and answers...

4. Tony is 18 months old and around 5 pm when his father usually comes home, he looks at his mother and asks “Dada?”? His mother knows that Tony is asking if his dad is coming home soon and answers accordingly. Consistent with language development, this example is best characterized as Tony using a: