A
The student isn't in class today. He had a fever yesterday.
The student who had a fever yesterday isn't in class today.
MY flight is 168. It goes to Chicago.
My flight which goes to Chicago is 168.
Diane Johnson is my neighbor. She works at the bank.
Diana Johnson who works at the bank is my neighbor.
I can't find the key. It fits in this lock.*
I can't find the key which fits in this lock.
That man is my favorite teacher. He teaches math.
That man who teaches math is my favorite teacher.
He has a cold. It's getting worse every day.
He has a cold which is getting worse every day.
The taxi hit a pedestrian. He was crossing the street.
The taxi hit a pedestrian who was crossing the street.
Ted didn't see the car. It went through the stop sign.
Ted didn't see the car which went through the stop sign.
I had a good instructor. She knew how to teach.
I had a good instructor who knew how to teach.
You should go to the mall. The mall has three floors.
You should go to the mall which has three floors.