The verb ser is used to talk about inherent attributes, qualities and characteristics that are not likely to change.

El barco es grande.
     The boat is large.
El carro es pequeño.
     The car is small.
Mi carro es rojo.
     My car is red.
Mi hermano es alto.
     My brother is tall.
El banano es dulce.
     The banana is sweet.
El niño es guapo.
     The boy is handsome.
Este río es muy ancho.
     This river is very wide.
El bebé es feo.
     The baby is ugly.