1. "Instead of going to the movies, we stayed home and watched a film." Here, "instead of going to the movies" is a gerund phrase acting as a preposition, indicating the alternative to going to the movies.
2. "Without thinking twice, he jumped into the pool." The phrase "without thinking twice" is a gerund phrase acting as a preposition, showing the condition under which he jumped.
3. "For being such a good dog, he got a treat." "For being such a good dog" is a gerund phrase functioning as a preposition, expressing the reason for the treat.
4. "Concerning moving to a new city, they had many questions." "Concerning moving to a new city" is a gerund phrase serving as a preposition, indicating the topic of discussion.
5. "Upon finishing the project, she felt a sense of accomplishment." "Upon finishing the project" is a gerund phrase acting as a preposition, indicating the time when she felt a sense of accomplishment.
Important Note: Gerund phrases as prepositions are less common than other types of prepositions. They tend to be more formal and often occur in specific contexts like the examples above.