1.Can you hear the bird singing in the tree?
Q:為什麼第一句是動詞原型?
A: 因為前面有助動詞 Can, 所以對應的動詞要是原型
ex:
Can you tell me the answer to this question?
Do you know the person who was talking to you?
2.I felt the floor shaking.
Q:為什麼第二句卻是過去式?
A: 因為事情發生在過去, 所以用過去式. (現在已無)
I felt =(那個時候)我感覺..
I feel =我(常態地)感覺..
3.Cindy cried out when she saw a motorcycle bump into her cat.
Q: 第三句為什麼bump不是過去式see卻是?
A: 同上面第二句.
..she saw =(當時)她看到..
看到什麼? 看到: "a motorcycle bump into her cat" 這件事
..she saw 後面接的是"事件": a motorcycle bump into her cat
那麼 bump 這字就不應該是 bumped, 因為前面有 saw.
如果一定要用 bumped 就要用 that 把兩個動詞隔開: ... she saw that a motocycle bumped into her cat.