Ser & estar: identity and state

• Review
• Ser
• Estar
• However

Review

Ser expresses identity, while estar expresses state, condition or location. Here is how it works in more detail:

Ser

• For personal characteristics (physical or non-physical) and defining characteristics of things or people, we generally use ser:

El perro es grande. Tu tío es muy alto. La casa es roja. Mi hija es muy simpática.

• For professions, we use ser. They can change, but we consider them part of people's identity.

Pedro es dependiente. Yo no soy cocinero, soy cantante.

Estar

• For people's feelings, or for the state or condition of things or people, we generally use estar:

Mi padre está muy cansado. Ella está triste. Estoy preocupado.

• For location, we always use estar, even for places that never move:

Yo estoy en Nueva York. Mi tío siempre está en su casa. La Casa Blanca está en Washington DC.

However

With some specific attributes, we can choose to use either ser or estar, depending on what we mean:

María está feliz means she is happy now; it is her current state.

María es feliz means being happy is part of her identity; we are making it a defining trait.

This is commonly done with feliz, guapo, hermoso, gordo, delgado, fuerte, débil, viejo, alegre, and nervioso. A special case would be aburrido: estar aburrido means being bored, while ser aburrido means being boring.

Unfortunately, there is no specific or logical rule that tells us which adjectives can work with both ser and estar.