What Is Their Main Difference?
Modal Verb Shall
Origin of Shall
Modal Verb Should
'Should' is also a modal verb. It is used to give or ask for advice and talk about assumptions. 'Should' is the past tense of the modal verb 'shall.' Have a look:
Talking About Certainty
'Shall' is used when we are certain that something will happen in the future:
We use 'should' when we are uncertain about the situation:
Talking about Necessities
When we want to talk about the law, mandatory events, and actions that must be done, we use 'shall.' This is mainly used in official documents and formal contexts. 'Should' cannot be used in this context as it conveys uncertainty. For example:
We use 'should' to ask for and give advice. In this form, we are expressing what we think is the right thing to do. 'Shall' cannot be used in this context as it will convey the wrong message and will sound like we are giving an order. Have a look:
Talking about Assumptions
We mentioned earlier that 'should' is past tense, but when it comes to talking about assumptions, it refers to the present and the future. Have a look:
We use 'shall' in formal contexts to make offers. To make offers with 'shall,' we need a first-person singular or plural pronoun 'I' or 'we.' Watch:
'Shall' is used in formal contexts while 'should' is less formal.
Negation and Question
We can create negative sentences with 'shall' and 'should:'
To do so, you simply add 'not' to the modal verb as illustrated below:
- Shall → Shall not
- Should → Should not → Shouldn't
To make yes/no questions, we put the modal verbs at the beginning of the sentence followed by the subject and the main verb. For example:
With Other Modal Verbs
We use only one modal verb in a sentence. We cannot use modal verbs with other modal verbs. Take a look at these incorrect sentences:
shall can defeat my enemy.
might should reconsider his behavior.
You may hear 'shall' in conditional type 1 statements, but this usage is mainly dedicated to dialects.