Nearly every student of Spanish from time to time faces the dilemma: “Which one to use this time?!”
The fact that there is only one verb “be” in the English language makes the whole bit rather confusing. But let's see start with some evident cases.
ser and estar with nouns and adverbs
The verb estar cannot be used with nouns:
Mi padre es profesor – My father is a a teacher
Somos españoles – We are Spanish.
Es una niña – She is (just) a girl
We must use ser with nouns even if they express a temporal state of things:
Eras una niña y ahora eres una chica mayor – You were just a girl and now you are an adult
Mi padre era profesor y ahora es conserje – My father was a teacher and now he is a janitor
With adverbs, we must use estar:
El mercado está lejos – The market is far
Estoy muy bien – I am fine
ser and estar with adverbials of place and time
If the subject is an object or a person we must use estar:
El mercado está enfrente –The market is in front
Mis padres están en casa – My parents are at home
¿Dónde está el auditorio? – Where is the auditorium?
If the subject is an event we must use ser:
La boda de mi primo será mañana en el Ayuntamiento – My cousin's wedding will be tomorrow at the city hall
¿Dónde es el concierto? – Where is the concert?
El concierto es en el auditorio – The concert is in the auditorium
ser y estar with adjectives
Both verbs can be used with adjectives.We will see it thoroughly in the next lesson. At the moment, remember that with emotion states we must use estar:
CORRECTO: Estoy triste – I am sad
INCORRECTO: *
Soytriste