1. Relative clauses

2. Relative clauses 1. Used to link two sentences with a common IDEA • In 1937 H. Constant designed a compressor. • This compressor / It ran in 1938 but failed mechanically.

3. Relative clauses 2. The relative pronoun replaces the common element the second time it appears

4. To join sentences using a relative: • Locate the first appearance of the common element. In 1937, H. Constant designed a compressor. • Add an appropriate relative after the common element In 1937, H. Constant designed a compressor which...

5. To join sentences using a relative: 3. Add the second sentence MINUS the repeated element In 1937, H. Constant designed a compressor which ran in 1938 but failed mechanically

6. Choice of relatives

7. Defining vs non-defining • Non-defining clauses are NOT necessary to distinguish who/what you are talking about. • Non-defining clauses go between commas. • No “that” in non-defining clauses • No omission of relative in non-defining clauses.

8. Omission of relatives possible iff • Relative pronoun is who(m), which or that • No comma before the pronoun (therefore, defining clause) • There is a noun/pronoun (subject) between relative and verb. Molecules absorb energy from the wall (that) they strike

9. Whose • If the repeated element shows possession, use “whose” as a relative adjective. • Whose is always followed by a name • Many high alloy steels are more difficult to cut than mild steel. • Their ingredients retard oxidation. →Many high alloy steels, whose ingredients retard oxidation, are more difficult to cut than mild steel.