The verb hay means “there is” or “there are”. This is an incredibly easy word to use—it never changes! Unlike other verbs, hay doesn’t get conjugated.
Hay un libro en la mesa. There is a book on the table.
Hay dos sillas en la oficina. There are two chairs in the office.
**Common Mistake: NEVER use “es” when you use “hay,” because “hay” already means “there is or there are”. You are saying “is” twice.
Hay es un libro en la mesa. Hay un libro en la mesa.
Past tense of “hay”
The past tense of “hay” is “había”. This verb doesn’t get conjugated either.
Había un libro en la mesa. There was a book on the table.
Había mucha gente en la fiesta. There were a lot of people at the party.