Please help me with these sentences.
1. I met my old friend by accident in a bookstore.
2. I accidently met my old friend in a bookstore.
3. I met my old friend accidently in a bookstore.
I think #1 & #2 are natural, and #3 is somewhat uncommon. Am I right?
Then what about these?
4. I broke the vase by accident.
5. I accidently broke the vase.
6. I broke the vase accidently.
I guess #5 is the most common and #6 is ok, but #4 is somewhat unnatural. Am I right?
Thank you very much.