1)there is a television set in the living room 2)there are two armchairs in the room 3)there is a bed in my room 4)there are books in the bookshelves поставить в время

1)There was a television set in the living room
2)There were two armchairs in the room
3)There was a bed in my room
4)There were  books in the bookshelves

вместо is  ставим  was ( ед.ч.)
вместо  are  ставим  were (мн.ч.)

1) There was a television set in the living room 2) There were two chairs in the room 3) There was a bed in my room 4) There are books on the bookshelves