The letter that I opened it wasn't for me.
The letter that I opened wasn't for me.
This isn't the train on that I normally travel.
This isn't the train on which I normally travel/ the train (that/which) I normally travel on
The reason for it I didn't know was that no one had told me.
The reason (why/that) I didn't know was that no one had told me.
That we should do is ring the police.
That we should do is ring the police.
Einstein who failed his university entrance exam discovered relativity.
Einstein, who failed his university entrance exam, discovered relativity.
The person we talked to were very friendly.
The people we talked to were very friendly.
Outside the door was a pair of boots covering in mud.
Outside the door was a pair of boots covered in mud.
The plane was twenty-five years old. It crashed.
that/which crashed was /// ,which crashed, was
One day Tessa was ill in bed. Martin rang.
The day (when/that) Martin rang (,) Tessa was
Some documents have been found. They were stolen from a car.
The documents stolen from a car have been
That map is out of date. You were looking at it.
(that/which) you were looking at is
The talk was very interesting. Judy gave it.
(that/which) Judy gave was /, which Judy gave, was
Janet solved the puzzle. She did it before everyone else.
the first (person) to solve /the first (person) who solved
