语法点：should / ought to 与 should have done (should & ought to)
should 和 ought to 都表示“应该”，用来提出建议、说明义务或表达“按理说会怎样”的推测，两者意思基本相同，ought to 语气略正式。should have done / ought to have done 则指向过去：本该做而没做，或本不该发生却发生了，常带有责备或遗憾的语气。与之相对的 need not have done 表示“本来不必做（却做了）”。本课讲一场糟糕的喜剧演出，很多本该登台的演员没来，观众本来不必失望，正是 should have appeared 和 need not have felt 的典型用法。
结构
| 形式 | 结构 | 例句 |
|---|---|---|
| 现在 / 将来 肯定 | 主语 + should / ought to + 动词原形 | You should queue early. |
| 现在 / 将来 否定 | 主语 + should not (shouldn't) / ought not to + 动词原形 | You shouldn't be so nervous. |
| 疑问 | Should + 主语 + 动词原形? | Should we rush to see it? |
| 过去（本该做而未做） | 主语 + should have / ought to have + 过去分词 | The artistes should have appeared. |
| 过去（本不该做却做了） | 主语 + shouldn't have + 过去分词 | He shouldn't have said that. |
| 过去（本不必做却做了） | 主语 + need not have + 过去分词 | They need not have felt disappointed. |
注意：should have done 只是说“本应如此”，事实上没有发生；must have done 才表示对过去的肯定推测。
课文中的例句
- [句 5] Those who failed to get in need not have felt disappointed, as many of the artistes who should have appeared did not come. — should have appeared 指演员“本该登台”却没来；need not have felt 指观众“本不必失望”
- [句 9] We all know what the poor man should have said, but what he actually said was… — should have said 与 actually said 对比，突出“该说的”和“实际说的”不同
- [句 3] We had to queue for hours to get in and there must have been several hundred people present… — must have been 是对过去的肯定推测，可与 should have done 对比记忆
- [句 1] People will do anything to see a free show--even if it is a bad one. — will do 表示一贯的习惯，与情态动词 should 表“应该”的语气不同
补充例句
- You should read the programme before the show begins. — 演出开始前你应该先看一下节目单。
- The advertiser ought to have practised his speech before he stood before the microphone. — 那位广告员站到话筒前之前本该先练习一下讲稿。
- We needn't have queued for hours; there were plenty of empty seats. — 我们本来不必排几个小时的队，空座位多得很。
易错点
- ❌ The artistes should appeared last night. → ✅ The artistes should have appeared last night. — 表示过去“本该做”必须用 should have + 过去分词，不能直接接过去式。
- ❌ He ought to not say that. → ✅ He ought not to say that. — ought to 的否定形式是 ought not to，not 放在 to 之前。
- ❌ They needn't have to feel disappointed. → ✅ They needn't have felt disappointed. — need not have 后接过去分词，表示“本不必”，不要再加 to。
- ❌ You should have to queue for hours. → ✅ You should have queued for hours. — should have 后直接接过去分词，不要混入 have to。