Відповідь:
1 I can help you with your homework, if you want.
I don't mind, help you with your homework
2 It's two weeks since I saw my friend Josh.
I Don`t see my friend Josh for two weeks.
3 Il's quite unusual for Ben to travel by bus.
Ben by bus very often.
4 There weren't many people in the cafe today.
There were very muth people in the cafe today.
5 Ted won't be a fast swimmer if he doesn't practise.
Ted won't be a fast swimmer without practises.
6 I think it would be a good idea to see the doctor.
You must to see the doctor.
7 This coat has Tom's name in it, so l'm sure it's his.
This coat has Tom's name in it, so it his.
8 I can't go to the concert because I don't have any money.
If I don`t have money,I could go to the concert.
9 Our English teacher wrote this poem.
This poem were written our English teacher.
10 A professional photographer took my photo.
I had taken photo by a professional photographer.
How many tennis balls you have?
I have few books about Russian history.
I have many tennis balls.
I haven't few books about Russian history
I haven't much more ideas
По-моему все правильно ✅ ,теннисные мячики и книги можете заменять чем то другим