Can You Croak?

There once was two children playing in the garden. They were being watched over by their grandpa. The eldest of the two, went up to their grandpa and asked, " grandpa, grandpa, can you croak?". The grandpa looked quite shocked to this sudden question and replied, "what do mean by croak?". The little child said "you know, make a noise like a frog". Such a pointless question the grandpa thought and quickly sent the child back to play.
Later on the youngest of the children came up to the grandpa. "grandpa, grandpa" she exclaimed, "can you croak?". Annoyed, the grandpa stared at the child and said, "why are you asking me to make a noise like a frog? ". The little child smiled at the grandpa and whispered "we overheard mummy and daddy saying that if you croaked, we get to go to Disney!"