Generally speaking, if you miss someone too much and are too afraid of losing someone, you will dream of his death. And miss the dead relatives, it is easy to dream that he is still alive, because dreams are not like reality, dreams are free, and dreams can be realized for things that cannot be realized in reality.
Dreaming that grandpa sells pears means that you are separated.
What you said to him in your dream is also your own truth. He came to you to show that you have always had him in your heart.
Dreaming of dead relatives, if their living conditions are not good in the dream, according to superstition, they are dead and short of money, so you should burn some paper money for grandpa.