PRESENTE SIMPLE
- there are twelve tables in this room (hay 12 mesas en esta habitación)
- there are not twelve tables in this room
- are there twelve tables in this room?
PASADO SIMPLE
- there were twelve tables in this room (había 12 mesas en esta habitación)
- there were not twelve tables in this room
- were there twelve tables in this room?
FUTURO SIMPLE
- there will be twelve tables in this room (habrá 12 mesas en esta habitación)
- there will not be twelve tables in this room
- will there be twelve tables in this room?