For this case we must translate the following sentence into Spanish:
"Is this your chair"?
It is noted that the sentence is a question asked to a second person
We have to:
Chair translates as "silla"
This translates as "Esta"
your translates as "tu" (which belongs to the subject of the sentence)
Then the sentence in Spanish would be:
¿Es esta tu silla?
Answer:
¿Es esta tu silla?