Ser o no ser ó estar o no estar? :=)

Yo soy española y tú, ¿de dónde eres?
Look at this video
Now, when do we use verb to be? See uses and examples:

When we describe physical and personality we use adjectives. Adjectives must agree in gender and number.
For example:
Yo soy simpática. Femenine and singular because I am a girl and a single one.
Tú eres simpático. To be honest, I have not idea if you are a boy or girl, maybe you are more that one. Try to figure it out.
Él es arrogante/ella es arrogante. Same ending for both masculine and femenine form.
Ellos son inteligentes. Plural. When we speak about a group of people.
Nosotros somos flojos. We use the masculine form, even if in this group are male and female.

It is time to practice. If you have any question just book a lesson here
There are interactive lesson you might be interested to try. Click here