There is often confusion for English speakers when using hay and está. Let's see the difference:
Hay means "There is/there are". We use hay when we are talking or asking about the existence of something/someone.
Generally the order can present itself in two ways, here's the first:
Here's the second way:
You can use the plural definite articles unos/unas but very often we omit them as they are not necessary:
"Está" means "It is" and "están" means "They are". We use estar to locate things/people somewhere.
The general order of the sentences with estar is:
Have a look at how we would use both hay and está in a simple conversation:
Someone is asking about the existence of a park nearby. Notice how after hay we use the indefinite article "un" (the same way in English the indefinite article "a" is used)
Once the speaker knows there is one, he/she asks where it is:
Notice how now they are using "está" to locate it. Now they don't use the indefinite article "un/una" but the definite article "el/la" (the same way in English "the" is used)
- Using el or la to say the (singular definite articles)
- Using los or las to say the (plural definite articles)
- Using un, una to say a/an (singular indefinite articles)
- Using unos, unas + plural nouns to say some / a few (plural indefinite articles)
- Using hay = there is / there are
- Using estar (not ser) when talking about locations
You can also watch this video with Gordon and Cynthia from Lightspeed Spanish explaining how hay and está works.