Shall and should are two modals that have lost much ground in modern English. Shall was once used to express authority, determination, and formal future. Today, it survives mainly in offers, suggestions, and requests for advice. Should primarily expresses advice, reproach, and optimistic prediction. These two modals are remnants of a more formal English, but they remain essential in certain contexts. Welcome to the world of shall and should — where authority meets advice.
SHALL: Five Functions (some archaic)
1. Strong authority from the speaker (archaic usage)
The speaker imposes a firm obligation on the subject with almost biblical authority.
- You shall not kill. / Thou shalt not kill.
- You shall follow the rules or face the consequences.
This usage is archaic in modern everyday English. It's found mainly in:
- Biblical or religious texts
- Very formal legal texts
- Archaic or solemn style
Modern alternative: You must follow the rules or simply Follow the rules.
2. Optimistic and determined prediction (aging usage)
The speaker expresses a prediction full of determination to encourage.
- Stay positive, and things shall work out in your favour.
This usage is falling into disuse. It sounds literary or inspiring, but not common. Modern alternative: Things will work out in your favour.
3. An offer
The speaker proposes to do something for the interlocutor.
- Shall I get you a cup of tea?
This is one of the still living uses of shall in British English. Typical formula: Shall I + verb?
4. A suggestion
The speaker suggests doing something together.
- Shall we go out for dinner tonight?
Typical formula: Shall we + verb? Common variant: Let's go out for dinner, shall we? (tag question) This is also a still living usage, especially in British English.
5. A request for advice
The speaker asks for opinion or advice from the interlocutor.
- Shall I take the job offer?
Typical formula: Shall I + verb? The speaker is asking: "Do you think I should...?"
SHOULD: Four Main Functions
1. Personal advice from the speaker
The speaker gives advice to the subject.
- You should wear a coat; it's cold outside.
Should is less strong than must (obligation) but more insistent than simple could (possibility). Nuance: It's advice, not an order. The subject remains free to follow or not.
2. Reproach from the speaker
The speaker reproaches the subject for not having done something.
- You should listen carefully.
→ Implied: "You're not listening carefully enough." With HAVE + past participle (reproach about the past):
- You should have done it differently.
→ The subject did not do what they should have done. It's a retrospective reproach. Note on French translation: In French, reproach is expressed with the conditional present or past:
- Tu devrais écouter. (conditional present)
- Tu aurais dû le faire autrement. (conditional past)
This is called an "obligation in the conditional," halfway between advice and obligation. Why this difference between French and English? In English, must cannot be put in the conditional. In French, "devoir" can. So should often translates the conditional of "devoir" in French.
3. Mitigated optimistic prediction (if all goes well)
The speaker expresses a positive prediction, but conditioned by circumstances.
- If the weather holds up, we should have a perfect day for the outdoor event.
Nuance: It's not certain, but a reasonable probability if conditions are met. Should is less certain than will, but more optimistic than might.
4. Optimistic prediction in the past (sequence of tenses)
In reported speech or sequence of tenses, should replaces shall in the past. Direct speech:
- It's likely that they shall succeed.
Reported speech (past):
- It was likely that they should succeed.
This usage is rare and formal in modern English.
SHALL vs SHOULD: Key Differences
SHALL (limited usage today):
- Strong authority: You shall follow the rules. (archaic)
- Determined prediction: Things shall work out. (aging)
- Offer: Shall I get you tea? (still living)
- Suggestion: Shall we go? (still living)
- Request for advice: Shall I take the job? (still living)
SHOULD (common usage):
- Advice: You should wear a coat.
- Reproach: You should listen. / You should have done it differently.
- Optimistic prediction: We should have a perfect day.
- Sequence of tenses: It was likely they should succeed. (rare)
Strength nuances: For obligation/advice:
- MUST: strong obligation (you absolutely must)
- SHOULD: advice or reproach (you should)
- COULD: possibility or light suggestion (you could)
For prediction:
- WILL: certainty or strong probability
- SHOULD: reasonable probability (if all goes well)
- MIGHT: reduced possibility
Conclusion
Shall and should are modals that have evolved. Shall was once a modal of authority and formal future. Today, it really only survives in:
- Offers (Shall I help you?)
- Suggestions (Shall we go?)
- Requests for advice (Shall I accept?)
The authority and determined prediction uses are archaic or literary. Should is much more alive and expresses:
- Advice (You should rest)
- Reproach (You should have told me)
- Optimistic prediction (We should arrive on time)
In French, should often translates as the conditional of "devoir": "tu devrais" or "tu aurais dû". Mastering shall and should means understanding that English has declining modals (shall) and living modals (should), and knowing how to navigate between advice, reproach, and suggestion with appropriate force.