Hello, everyone! I’m Sveta. I’m 20. My English is not very good, but I want to speak English as I need to for my studies. I've decided to study English every day from today onward. I need help. I make a lot of mistakes. Please check my exercise: 

1. He threw his bag on the floor.
2. Ann's mother likes to travel by plane.
3. Why are flies flying around us?
4. Our manager can’t answer; he has flown to Germany for a conference.
5. Tim flew away last week.
6. Mom gave me a pair of gloves and a scarf, because it’s cold and snowy outside. 
7. Nick is married, but he has gone away for the weekend alone. 
8. My father got married to my mother 25 years ago. (yes you do need to use my) No, you didn’t mishear, they have been married for 25 years. My parents will have their 25th anniversary this year.
9. My teacher from school always gives me advice. (advice is always singular - you might find it helpful to research countable and uncountable nouns).
10. I will buy a new dress to wear to my sister's wedding. Oh, Sara is very beautiful; she has worn her new dress. 
11. When I was younger I never wore dresses and skirts but now I do.
12. My friend spent all the money he had at a nightclub. 
13. I’m blowing on my finger, because a bee has stung me.
14. He stings like a wasp.

I make a lot of mistakes. Check my exercise, please.