The verb “ser” corresponds to the English verb “to be”. Some of the most common uses are:

1. To describe people or things.

• Yo soy David (I’m David)
• María es hermosa (Maria is beautiful)
• Los gatos son blancos (The cats are white)
• Esa silla es muy pequeña (That chair is very small)

2. With nationalities or origin.

• Ella es coreana (She is Korean)
• Soy de Bogotá (I am from Bogota)
• Son cervezas de Alemania (They are German beers)

3. With religions

• Ella no es católica (She is not Catholic)
• Mi amigo es musulmán (My friend is Muslim)

4. With occupations or professions

• Arturo es profesor de química (Arthur is a teacher of Chemistry)
• Soy vendedor de seguros (I am an insurance seller)
• Somos estudiantes de idiomas (We are language students)

5. With dates and time

• La reunión es a las 5 p. m. (The meeting is at 5 p.m.)
• Hoy es miércoles (Today is Wednesday)
• El cumpleaños de Susana será el 15 de mayo (Susana’s birthday will be in May 15th)

6. With materials that things are made of

• La camisa blanca es de seda (The white shirt is made of silk.)
• La cadena es de oro puro (The chain is made of pure gold.)

7. With relationships

• Ella es mi madre (She is my mother)
• Carlos es mi jefe (Charles is my boss)
• Pedro y felipe son hermanos (Peter and Philip are brothers)
• Andrea fue mi mejor amiga (Andrea was my best friend)

8. With locations but ONLY of events

• La boda fue en la catedral central (The wedding was held at the Central Cathedral)
• La conferencia será en el centro de convenciones (The conference will be at the Convention Center)

9. To indicate possession

• El auto blanco es mío (The white car is mine)
• Esas joyas son de mi esposa (Those jewels are my wife’s)

10. When “ser” and “estar” are correctly possible, “ser” must be used to indicate something permanent and “estar” to indicate something temporary. (Note: This rule is applicable only when both verbs are possible).

• Soy feliz (I am happy) It implies a permanent or mostly state of happiness. Ex. Soy una persona feliz (I am a happy person)
• Estoy feliz (I am happy) It implies a temporary state of happiness. Ex. Estoy feliz hoy (I am happy today)
• Ella es muy irritable (She is irritable) (Almost always)
• Ella está muy irritable (She is very irritable) (at this moment)