Did you go shopping with your parents?爲什麼shopping不用原形?

題目：

Did you go shopping with your parents?爲什麼shopping不用原形?
Do you think everyone enjoys their weekend?爲什麼enjoys不用原形?He likes reading book.---Does he like reading book?爲什麼reading不用原型?
問題是不是疑問句用動詞原型嗎？

解答：

第一句的謂語是think,用了原形,其後的賓語從句仍使用陳述句形式,everyone 是單數,故用enjoys.
第二句的謂語是like,用了原形,表示喜歡某事,用like doing sth,故用reading