News, which is run by rich people, is biased.
News that is run by rich people is biased.
When we don’t use commas (only with that) it means the information is essential. That there is still hope! Not all newspapers are run by rich people.
Drugs, which make you stupid, should be illegal. (All drugs make you stupid and should be illegal)
Drugs that make you stupid should be illegal. (Only drugs that make you stupid should be illegal)
They like me making fun of news and any time I can mention drugs they tend to listen a little more 🙂
There’s also the fact that can be used for people and which is NEVER used for people (they usually grasp that pretty fast, but sometimes they mess up)
Blumer Editorial 
As a teacher my students sometimes struggle with this, I have a few games I play with them to practice: http://eslcarissa.blogspot.com/2012/10/which-vs-that.html but I found a few examples they really like.
News, which is run by rich people, is biased.
News that is run by rich people is biased.
When we don’t use commas (only with that) it means the information is essential. That there is still hope! Not all newspapers are run by rich people.
Drugs, which make you stupid, should be illegal. (All drugs make you stupid and should be illegal)
Drugs that make you stupid should be illegal. (Only drugs that make you stupid should be illegal)
They like me making fun of news and any time I can mention drugs they tend to listen a little more 🙂
There’s also the fact that can be used for people and which is NEVER used for people (they usually grasp that pretty fast, but sometimes they mess up)
Thanks for chiming in!