How proper is your grammar?

Are you well spoken, or have you not yet mastered your own language?

1 Which is the missing word? I _____ John at the supermarket today.
2 Which of these statements is correct?
3 Which is the missing word? ____ I please have some cake
4 Which of these statements is correct?
5 Which of these statements is correct?
6 How would you address a group of people?
7 Which of these statements is correct?
8 Which is the correct answer to the question, "how are you doing?