I usually just swim during the summer at my friends house
Your instructions are very unclear.
Sports are fundamental to one's health. If sports or exercising in general was deducted from one's daily life style they will most likely suffer. Not being active has harsh consequence on one's body. One may gain weight, have weaker bones, and weaker muscles. Everyone should participate in sports or some type of physical activity to avoid these problems. Such as playing: Basketball, Volleyball, Football, Soccer, Skateboarding, Tennis, or Frisbee Golf. Sports also have a link to attitudes and outlooks. When put into groups and needing to use teamwork, people who play sports tend to be at ease and have no problems working in groups. Sports is a good way to keep your health in check and helps you deal with life such as group projects and office work.
Adding -s is the most common. for example: books, cups, pencils, etc. -es might have been the one that confused you, but that isn't a super common ending for plurals--instead, a more common one would be "-ies" which is when you drop the y (berry becomes berries, for example).
Doubtful, unbelieving, dubious, unconvinced,
