E.g.
I once knew a classmate who always failed in class. When it was nearing to the major examinations, I offered to study with that classmate. Found out he/her had been lagging behind due to financial crisis at home, he/she had to hold a part time job outside to help out the family. Thus he/she was often tired and could not concentrate studying.
We spent days studying hard together. When results were out, we both did well. And I made a new friend too.
