ought to/should ¹

两者都可以, 而且在语义上并没有什么明显的区别。只是 should 比 ought to 更为常见罢了。CGEL 指出, should 和 ought to 在表示“义务”或“职责”时具有相同的含义:

1. You $\$left\{\begin{array}{l} should \\ ought to \end{array}\right\} do as he says. 你应当按他说的去做。

2. The floor $\$left\{ \begin{array}{l} should \\ ought to \end{array} \right\} be washed at least once a week. 这地板至少一周要擦洗一次。在表示“推论”时，亦具有相同的含义：

3. The mountains $\$left\{\begin{array}{l} should \\ ought to \end{array}\right\} be visible from here. 从这里应当看得见山。

4. These plants $\$left\{\begin{array}{l} should \\ ought to \end{array}\right\} reach maturity after five years. 这些植物在五年之后应当长成熟。

5. Henry ought to be here soon — he left home at six. 亨利应该很快就到——他是六点钟从家里出来的。