What does hay mean in Spanish?
The short answer
Hay means “there is” or “there are” when you say that something exists or is available. The form stays hay with both singular and plural nouns: Hay una mesa and Hay dos mesas.
Look, count, then say it

Describe the keys and the book. Complete both sentences with the same word.
___ dos llaves en la mesa.
___ un libro en la mesa.
Show example answers
Hay dos llaves en la mesa.
There are two keys on the table.
Hay un libro en la mesa.
There is a book on the table.
Hay stays the same for one book and two keys. Here you are introducing what exists in the scene.
Introduce something that is there
Picture walking into a room and describing what you see for the first time. Hay lets you introduce those things. It works with a number, an indefinite article or a quantity expression.
Hay una mesa junto a la ventana.
There is a table next to the window.
You introduce a table rather than identify the location of a previously mentioned one.
Hay tres sillas en la cocina.
There are three chairs in the kitchen.
Tres sillas is plural, but hay does not change.
Ask whether something is available
Use the same form in a question. In writing, include the opening and closing question marks. You can ask about a nearby place or an item you need.
¿Hay una farmacia cerca?
Is there a pharmacy nearby?
The question asks whether a pharmacy exists nearby, without naming a particular one.
¿Hay leche?
Is there any milk?
A quantity does not have to be stated.
Say no hay when something is absent
Put no immediately before hay. This is useful when an item has run out or when you want to say that no problem exists. Keep the phrase together when you practise recalling it.
No hay pan.
There is no bread.
Hay remains the same in the negative.
No hay problema.
There is no problem.
A useful complete expression for an everyday response.
Try it yourself
Complete the sentence for the situation. Say it aloud before revealing the answer.
Say that there are two chairs. Start with a capital letter.
___ dos sillas.
Check answer 1
Hay dos sillas.
Use Hay for existence; the plural noun does not change this form.
Ask if there is a pharmacy nearby. Capitalise the first word.
¿___ una farmacia cerca?
Check answer 2
¿Hay una farmacia cerca?
A question about existence also uses hay.
Say that there is no bread.
No ___ pan.
Check answer 3
No hay pan.
No hay means there is not or there are not.
Make it your own
Look around you. Say two sentences beginning Hay… and one beginning No hay… Then look away and recall all three.
Usage references
These Spanish-language references support the usage explained here. Examples, dialogues and exercises are written for Bilvo.