Usage of Shall and Should

"Shall" indicates a mandatory requirement, command, or strong future intention, often in formal or legal contexts. In contrast, "should" conveys advice, a recommendation, a polite request, or a soft obligation, indicating something that is expected or desirable but not strictly mandatory. In modern everyday English, "will" is often used instead of "shall" for future events.

When to use "Shall"

Formal Requirements:

"Shall" is used to state a mandatory rule or requirement, especially in official documents or legal contexts.

Example: The system shall have password protection enabled.

Strong Commands or Assertions:

It can indicate a forceful intention or command about a future action.

Example: You shall not enter this restricted area.

When to use "Should"

Advice and Recommendations:

"Should" is used to offer suggestions or advise someone on what is best or correct to do.

Example: You should stay home if you're feeling unwell.

Soft Obligations or Duties:

It can express a moral obligation or something one is expected to do.

Example: I should call my parents more often.

Probable or Hypothetical Situations:

"Should" can also refer to situations that are likely or may occur under certain conditions.

Example: If it should rain, we will move the event indoors.

Key Distinction in Rules and Documents

A requirement written with "shall" is mandatory and a deviation would be considered a noncompliance.

A suggestion written with "should" is a recommendation, and deviations are permissible if the situation warrants it, as it implies flexibility rather than strict compliance.