Dr. Jenkins knows the man to whom the letter was addressed . He is a man whose actions speak louder than words . Commas should not be used to set it off from the rest of the sentence. Adjective clauses introduced by that are always restrictive. Henry designed a car that has won a prize .
Adjective clauses are useful in combining two or more simple sentences into a complex sentence.
We lost the track meet. It was held last Wednesday. We lost the track meet that was held last Wednesday . Often the clause can be transformed into a participial phrase or and infinitive phrase . Karen, who was prepared to debate , led the information discussion of Russia.