Questions & Answers about Mi casa está allá.
Spanish often uses estar for location.
So for saying where something is, you normally use estar, not ser.
By contrast, ser is used for identity, classification, origin, and similar ideas:
- Mi casa es grande = my house is big
- Es mi casa = it is my house
So here, because the sentence is about where the house is located, está is the correct verb.
Está is the third person singular form of estar in the present tense.
That means it can mean:
- he/she/it is
- you are (formal singular, usted)
In this sentence, it matches mi casa, which is grammatically third person singular:
- mi casa → está