1. "Are you here for business or for pleasure?"
Are you here for business or for pleasure? Because we need you to stay on track.
2. "I am here on business, not for pleasure."
Sorry, Sir, this was an accident. I am here for business, not for pleasure, of course. 
3. "My mother office receives a lot of business letters every day."
My mother's office receives a lot of business letters every day, because she works at a big company.
4. "Please help her to find her book."
Please help her to find her book. She needs it for her lesson in five minutes.
5. "At last, they found their way in the forest."
At last, they found their way in the forest. By that time, they had grown weak and weary. 

Надеюсь, что правильно поняла Вас и как-то помогла.