Simple:
* The comedian will cohost the awards ceremony with a popular actress.
* My friend and I decided to cohost a dinner party for our mutual friends.
More complex:
* The talk show's new cohost brings a fresh perspective to the conversations.
* The conference organizers announced that a well-known entrepreneur would cohost the keynote panel.
* The cohost of the podcast expertly guided the conversation between the guests.
Informal:
* I'm excited to cohost a game night with you guys!
* We decided to cohost a potluck, so everyone could bring their favorite dish.
Remember, "cohost" always refers to someone who shares the hosting responsibilities with another person.