exercise 可以是動詞“鍛鍊”，如 He exercises every day. 此時，exercises 是 exercise 的單三形式。exercise 也可以是名詞。 （1）“練習”，“操”可數名詞 如 There are many exercises in the book. We should do eye exercises. （2）“鍛鍊”，不可數名詞 如 Let"s take exercise.

1.各種起到鍛鍊身體作用的活動是 exercise ，不可數。動詞搭配用take.You"ve put on weight! Better take exercise every day.

2.有規律的或有規則的操練只用exercises。如：眼保健操、廣播體操等。動詞搭配用do.We do eye exercises during the break.

3.與知識學習有關的練習是可數名詞，有單複數之分。動詞搭配用do.Today,I"ll give three exercises to do.