The charity that is a trifle to us can be precious to others. (Homer)

Here are some questions to help you talk about charities in English and here are some more. Have a look at these questions for a pairwork activity. This page by BBC Learning English is also well worth checking out. 
I am only one, but I am one. I cannot do everything, but I can do something. And I will not let what I cannot do interfere with what I can do. (Edward Everett Hale)