user_query: Check off two items on the grocery list
response_text: Which item?
user_query: actually check off two items on the 
response_text: Are you sure you want to go ahead and clear it?
user_query: Add two items to the grocery list
response_text: What do you want to add?
User: I would like to see this month's bill in pdf, no, word.
Parse: Get_bill ( billing_date_span « this month » document_format « word » )