Question

I----- my grand father's house in those days

Answer 1

I lived at. my grandfather's house in those days.

Answer 2

I lived at my grandfather’s house in those days

EXPLANATION:

• The above is an instance of using prepositions. Prepositions are words used to link pronouns, phrases, or nouns to other words in a sentence. They act to link the objects, people, locations and time of a sentence.
• Prepositions are generally 'short words', and they are usually placed in front of nouns. The preposition at is used to speak about specific locations in cities or the countryside a certain person’s residence if the place is specified.