Answer:
You use Ser when things are permanent or long lasting. To remember this there is an acronym:
Descriptions: names or physical descriptions
Occupations: jobs or things to fill up time
Characteristics: to describe someone
Time: days, dates, years, or time
Origin: where someone or something is from
Relationships: family, friends, or relationships
You use Estar when things are temporary. The acronym to remember for this is:
Position: physical position
Location: of someone or something but there is an exception: ser is used for parties
Ex: La fiesta es en mi casa
Action: ongoing actions
Condition: physical and mental
Emotion: how a person is feeling at that moment
Examples:
Ser:
1. Bob es ingles. Bob is English.
2. Tu eres estudiante. You are a student. (sometimes articles aren't used)
3. Ella es intelligente. She is intelligent.
4. Hoy es jueves. Today is Thursday.
5. Esta fruta es de California. This fruit is from California.
6. El es tu padre. He is your father.
Estar:
1. Tus amigos estan sentados. Your friends are seated.
2. Nosotros estamos en el cafe. We are is the cafe.
3. Mi hermana esta lavando los platos. My sister is washing the dishes.
4. Yo estoy cansado. I am tired.
5. Yo estoy feliz. I am happy.
Hope this helps!