1. Defining & Non-defining Clauses - LEARN & USE … 04/05/2015Chris Snuggs - Sentence Construction 1  Joseph Salk, who invented the polio vaccine, made a fantastic contribution to humanity. The phrase "who invented the polio vaccine" is NOT ESSENTIAL to know who we are talking about. Therefore it is "NON-DEFINING" and is COMMARED OFF. You can TEST this by seeing if an inserted phrase can be left out …. e.g. Joseph Salk made a fantastic contribution to humanity. (YES, IT CAN!) Punctuate this sentence correctly!  joseph salk who invented the polio vaccine made a fantastic contribution to humanity

2. Defining & Non-defining Clauses - LEARN & USE … 04/05/2015Chris Snuggs - Sentence Construction 2  The man who invented the polio vaccine made a great contribution to humanity. Without "who invented the polio vaccine" we can't identify the SUBJECT and so this phrase is ESSENTIAL to understand the meaning. Therefore IT IS NOT COMMARED OFF. Do the test again. Can the inserted phrase be left out? The man made a fantastic contribution to humanity. (NO, IT CAN'T - without the missing clause it doesn't make sense!)  the man who invented the polio vaccine made a great contribution to humanity

3. Defining & Non-defining Clauses - LEARN & USE … 04/05/2015Chris Snuggs - Sentence Construction 3  milk which is a nutritious and balanced food is relatively cheap compared to other foods "which is a nutritious and balanced food" is NOT NECESSARY to know exactly what is the SUBJECT of the sentence. Therefore it is NON-DEFINING and is COMMARED OFF.  Milk, which is a nutritious and balanced food, is relatively cheap compared to other foods.

4. Defining & Non-defining Clauses - LEARN & USE … 04/05/2015Chris Snuggs - Sentence Construction 4  Milk which has been left out in the sun for an hour is likely to have gone off. "which has been left out in the sun" is ESSENTIAL to know what milk you are talking about. Therefore it is DEFINING and is NOT COMMARED OFF.  milk which has been left out in the sun for an hour is likely to have gone off

5. Defining & Non-defining Clauses - LEARN & USE … 04/05/2015Chris Snuggs - Sentence Construction 5  the nile flows from lake victoria which is one of the largest lakes in africa  The Nile flows from Lake Victoria, which is one of the largest lakes in Africa.

6. Defining & Non-defining Clauses - LEARN & USE … 04/05/2015Chris Snuggs - Sentence Construction 6  the nile which flows from lake victoria is the longest river in africa  The Nile, which flows from Lake Victoria, is the longest river in Africa.

7. Defining & Non-defining Clauses - LEARN & USE … 04/05/2015Chris Snuggs - Sentence Construction 7  chicago which is in the us has more poles than any other city except warsaw  Chicago, which is in the US, has more Poles than any other city except Warsaw.

8. Defining & Non-defining Clauses - LEARN & USE … 04/05/2015Chris Snuggs - Sentence Construction 8  The North Koreans who have defected to the south with fighter planes have received large sums as a reward.  the north koreans who have defected to the south with fighter planes have received large sums as a reward

9. Defining & Non-defining Clauses - LEARN & USE … 04/05/2015Chris Snuggs - Sentence Construction 9  the north koreans whom the pentagon believes have developed a nuclear device pose a great threat to seoul  The North Koreans, whom the Pentagon believes have developed a nuclear device, pose a great threat to Seoul.