Optional or Required? Marie Curie is the woman who discovered radium.
Required
Optional or Required? This is the house which Jack built.
Optional
Optional or Required? Economics is a subject that I've never understood.
Optional
I want a mobile phone that takes good photos. (Subject of the clause / Object of the clause / Possession)
Subject of the clause
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.
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? Will Smith is the actor whom my mom loves.
Optional
I have a friend whose father is a famous actor. (Subject of the clause / Object of the clause / Possession)
Possession
Optional or Required? Netflix is the streaming platform that people are using a lot these days.
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.
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.
The cellphone that I'd love to buy is...
Student's answer
My mom's the one who works in an office. (Subject of the clause / Object of the clause / Possession)
Subject of the clause.
My best friend is someone who is trustworthy. (Subject of the clause / Object of the clause / Possession)
Subject of the clause
