Sure! Here are five sentences using the phrases you requested:

1. I am **fond of** reading mystery novels in my free time.
2. She is **keen on** learning new languages and practices every day.
3. He is really **interested in** science and often conducts experiments at home.
4. They are **crazy about** traveling and have visited over twenty countries.
5. I’m really **into** photography lately and love capturing nature shots.