This site has a good explanation and a good memory tool.
Thank you for using the Jiskha Homework Help Forum. Try to "memorize" the following:
1. to express a quality or characteristic of the subject
ex. Este vino es de España.
This wine is from Spain
La casa es de madera.
The house is made of wood.
(It's a wooden house.)
Felipe es bueno.
Felipe is good. (always)
2. to describe or identify the subject
ex. María es alta (joven).
Mary is tall (young).
Mi coche es nuevo.
My car is new (brand new)
Mi hermano es médico (fuerte).
My brother id a doctor (strong).
Juana es rica (feliz).
Jane is rich (wealthy) (happy).
¿Quién es? Soy yo.
Who is it? It is I.
3. to express time and dates, and with impersonal expressions.
ex. ¿Qué hora es? Son las dos.
What time is it? It's 2.
Hoy es el 25 de octubre.
Today is October 25th.
Es necesario estudiar.
It is necessary to study.
4. to express an action when used with the past participle.
ex. Las ventanas fueron cerrados por la profesora.
The windows were closed by the teacher.
La puerta fue abierta por el niño.
The door was opened by the child.
1. to express location, position, or situation of the subject. (temporary situation)
ex. Madrid está en España.
Madrid is (located) in Spain.
¿Dónde está la casa?
Where is the house? (located)
Felipe está delante de la biblioteca.
Philip is in front of the library.
2. to indicate a state or condition of the subject.
ex. María está cansada (sentada).
María is tired (now) (seated).
El coche está lleno (sucio).
The car is full (dirty).
Ellos están alegres (tristes).
They are happy (sad).
Luis está enfermo (bien).
Louis is ill (sick) (well).
La puerta está abierta (cerrada).
The door is (temporarily) open (closed).
3. to form the progressive tense with the gerund.
ex. Están cantando.
They are singing.
They were playing
NOTE: If you have just begun Spanish, not all these examples will make sense to you. Save them for later!
CAUTION (here's the "trouble spot.")
Some adjectives may be used woith either ser or estar, but the meaning of the adjective will be different!
Es bueno (malo).
He is good (bad) = characteristic
Está bueno (malo).
He is well (ill). = condition
He is clever (smart). = characteristic
He is ready. = condition
He is pale-complexioned. = description, identification)
He is (looks) pale. = condition
It is safe (reliable). = description
He is sure. = condition; state of mind)
El color es vivo.
The color is bright. = description
He is aliv. = state; phase)
Es viejo (joven).
He is old (young). = description
Está viejo (joven).
He looks (seems) old (young). = condition
El es cansado.
He is tiresome. = characteristic
El está cansado.
He is tired. = condition, state
NOTE that adjectives used with ser and estar must agree in number (singular/plural) and gender (masculine/feminine) just like all adjectives.
Now, you might try "color coding" what doesn't want to stay with you = bilious green, yellow, etc. because that helps to "set" it in your mind.
Feel free to ask any questions you might have and one learns best by doing lots of examples!