How do i know when to use estoy estas esta estamos estais and estan

When you are telling where, how and the state of someone, examples: yo estoy aqui, that means that I am here and it's telling where I am, ustedes están enfermos, that means that you(plural) are sick, it is telling how you are, it's basically the same as in English, just that in is spanish the verb to be is divided into two meanings, ser/estar

Ithink los discos compactos.

Wet since patagonia is semi arid