Correct the incorrect, spot the errors

Q spot the errors 

1. My friend along with his parents were present.
2. Hardly had he came here when they started celebration.
3. I and my friends were present for the function.
4. I prefere coffee than tea in the morning.
5. He not only teaches maths but also sci.
6. The students hired a bus for its picnic.
7. All over the world people are speaking English.
8. He is good at mathematics 
9. I am angry with your performance.
10. He would go back to his word.
11. It is in 1985 , that I played cricket.
12. He told the servant that he will give him payment tomorrow.
13. Would you please tell me where can I find the post office?
14. I have few friends who always help me.
15. Lets go to party, will you?
16. Its very cold to tolerate.
17. It is  a plant that attracts insects.
18. I wish my friend was here
19. These flowers smell sweetly
20. Hardly he came when we were shocked.