Module 5 Rules and suggestions
7. should, ought to
1) should, ought to表示“應(yīng)該”，ought to表示義務(wù)或責(zé)任，比should語氣重。
i should help her because she is in trouble.
you ought to take care of the baby.
2) 表示勸告、建議和命令。should, ought to可通用，但在疑問句中常用should。
you should / ought to go to class right away.
should i open the window?
3) 表示推測(cè)
should , ought to (客觀推測(cè)), must(主觀推測(cè))。
he must be home by now. (斷定他已到家)
he ought to/should be home by now.(不太肯定)
this is where the oil must be. (直爽)
this is where the oil ought to/should be. (含蓄)