Here are the conjugated verbs for the sentences:

1. If Tim **forgets** doing homework, the **teacher** will give him a low mark.
2. Unless that dress **is** so expensive, I won't buy it.
3. Unless we **wear** coats, we **will feel** cold.
4. If Helen **earns** more money, she **will fly** to Canada.
5. If we **travel** to Tokyo, we **will visit** the art galleries.
6. If you **wear** sandals when climbing, you **will slip** on the rocks.
7. If Rita **finishes** her homework, the teacher **will give** her a high mark.
8. If you **go** to the bar, they **will listen** to loud music.
9. If you **wait** a minute, I **will ask** my parents to go out.
10. I **will not be** surprised if you **enjoy** that film.
11. If Helen **comes**, there **won't be** enough seats.
12. If they **work** hard, they **will pass** their exams.
13. We **will have** a barbecue if it **does not rain**.
14. If I **go** to London, I **will call** you.

Feel free to ask for anything else!