The cellphone that I'd love to buy is...
Student's answer
Optional or Required? Netflix is the streaming platform that people are using a lot these days.
Optional
I have a friend whose father is a famous actor. (Subject of the clause / Object of the clause / Possession)
Possession
Optional or Required? Marie Curie is the woman who discovered radium.
Required
My best friend is someone who is trustworthy. (Subject of the clause / Object of the clause / Possession)
Subject of the clause
Optional or Required? This is the house which Jack built.
Optional
He is the guy whom I went to the party with. (Subject of the clause / Object of the clause / Possession)
Object of the clause.
My dad's the one whose car is blue. (Subject of the clause / Object of the clause / Possession)
Possession.
Optional or Required? People who exercise have a better lifestyle.
Required
I don't know whom he gave the book to. (Subject of the clause / Object of the clause / Possession)
Object of the clause.
I want a mobile phone that takes good photos. (Subject of the clause / Object of the clause / Possession)
Subject of the clause
My mom's the one who works in an office. (Subject of the clause / Object of the clause / Possession)
Subject of the clause.
Optional or Required? Economics is a subject that I've never understood.
Optional
I work in that big yellow building that you can see over there. (Subject of the clause / Object of the clause / Possession)
Object of the clause.
Optional or Required? Will Smith is the actor whom my mom loves.
Optional
This is the dog which my sister adopted the other day. (Subject of the clause / Object of the clause / Possession)
Object of the clause.