--> Relative Clauses: (remember the chart we explained in class):
| Defining | 
No commas | 
That = who / which | 
(that, who, which) You can omit them.
 | 
| Non-Defining | 
,   , | 
Who / which. That is not allowed.
 | 
Who, which: cannot be omitted.
 | 
Click on this link.
http://www.ego4u.com/en/cram-up/grammar/relative-clauses#exercises
 
 


