Please, correct it

1. When we went yesterday at to the concert yesterday we saw a clamoring crowd.
2. This theater can seat only one hundred people.
3. Before the divorce they had a marriage counseling.
4. Rumor says that she conceived a child at last week.
5. This man is so mean spirited.
6. Stop stirring up I'm sure you will pass the exam. (stirring up doesn't sound natural, maybe use fretting?)
7. Stop yammering and go to work.
8. She is bragging about how rich is she.
9. Purpotedly the bottom line is low. (purportedly works but supposedly is more common)
10. The popularity has given him a bully pulpit.
11. This book contains meaningful quotes.
12. You should point out on her beautiful ring.
13. Ultimately she has quited her job.
14. I don't know is if there is a concealed truth. (hidden is more common)
15. All in all he can expressed contempt for this people.
16. The diversity of these books is huge.
17. Should be mandatory maternity leave be available for all mothers? (Sounds like a question. If you don't want it to be a question drop "should")
18. She advocated for the truth.
19. When it comes to speaking her mind she doesn't has problem with it.
20. She felt obligated to tell him the truth.

Very good!

Please, correct it

1. Yesterday when we went to the concert we saw a clamoring crowd.
2. This theater can seat only one hundred people.
3. Before getting a divorce, they had a marriage counseling.
4. Rumor has it that she conceived a child at last week.
5. This man is so mean- spirited.
6. Stop stressing, I'm sure you will pass the exam.
7. Stop yammering and go to work.
8. She is bragging how rich she is.
9. Purportedly the bottom line is low.
10. The popularity has given him a bully pulpit.
11. This book contains meaningful quotes.
12. You should point out her beautiful ring.
13. Ultimately she has quit her job.
14. I don't know if there is a concealed truth.
15. All in all he can express contempt for this people.
16. Diversity of these books is huge.
17. There should be mandatory maternity leave available for all mothers.
18. She advocated for the truth.
19. When it comes to speaking her mind she doesn't have a problem.
20. She felt obligated to tell him the truth.