Write four sentences using the subject "snowboarder" as a singular noun, a singular possessive noun, a plural noun, and a plural possessive noun.

1. Snowboarder descended down the mountain. 2. The snowboarder's skis are quite expensive. 3. Snowboarders have to be very careful while skiing. 4. Snowboarders' costumes have to be warm. 

The snowboarder is set to compete tomorrow. The snowboarder's name is John. A lot of snowboarders are going to be there and will stay for the night as well. The snowboarders' rooms are located at the third floor of the hotel.