Crear
The verb to be may vary according to the subject (singular or plural)
Cellphones are made of plastic and glass. They're used for calling
Subject + USED TO + infinitive verb + complement
A modal for activities in the past
A saxophone is used for playing music genres such as jazz and blues
IS USED FOR
Notebooks are made of paper
Its negative form is DIDN'T USE TO
Subject + verb to be + Past Participle Verb + complement
It has a contrast in the facts
IS MADE OF
It's a type of present tense
A chair is made of wood and it's used for sitting down
Pandas are found in Asia
The situations are not longer true
Those activities are not continued in the present