核心问题
At first I was of the opinion that you were decidedly right; ____ I am not sure. A. on the second thought B. on second thought C. on second thoughts D. on the second thoughts(《大学英语》1996年第3期) 书上给的答案是 C(on second thoughts)。难道不能选 B(on second thought) 吗?
词典解答
on second thought 也是正确的,主要用于美国英语,与 on second thoughts 同义。 I said I wouldn't do it, but on second thoughts(BrE)/on second thought(AmE) I think I will. (LDCE) 我本来说是不干的,但经过了再三考虑后,我想我还是干吧。
下面的托福题就没有让考生在 on second thoughts 与 on second thought 之间进行选择：
“Why didn’t you go to his party last night, John?” “____, I changed my mind.”
A. On a second thought B. By second thoughts
C. On second thoughts D. On the second thought (TOEFL)