The key answer of exercise 5

1. why you are studying English
2. how long you plan to study
3. what you do in the evenings
4. if / whether you have a full-time job
5. which countries you've visited
6. where you got that watch
7. if / whether there's a good café anywhere near here
8. if / whether you'd like to come for a coffee

Do you mind me asking ...? → os best for asking a very personal question.