The phrase 'Perhaps we ought to' is a polite and tentative way to propose an idea, making this a suggestion rather than a direct command or request.

The use of 'I expect' by a person in authority does not frame the action as optional. It is a clear and firm way of giving an order or command.

The use of 'Let's' (Let us) is a common way to make a suggestion for a joint action, inviting agreement rather than demanding compliance.

This is a very polite and formal request. The modal verb 'May' and the phrase 'trouble you' indicate that the speaker is asking for a favor, not issuing a command.

This sentence functions as a prohibition. The modal verb 'must' indicates a mandatory rule that forbids the use of mobile phones.

The phrasing 'would be delighted if you could join us' is a clear and warm expression used to invite someone to a social event.

Although phrased as a polite question ('Will you please...'), in a hierarchical context (like from a team leader), this is a directive or a polite order, not an optional request.

The phrase 'if I were you' is a classic structure for giving advice or making a suggestion. It frames the speaker's opinion as something for the listener to consider.

This sentence is a formal notice that forbids or prohibits unauthorized individuals from entering a specific area. The word 'restricted' clearly indicates a rule against entry.

The phrase 'You might want to' is a polite and indirect way of offering advice or a suggestion, rather than issuing a command.

The phrase 'are required to' indicates a mandatory action or a rule that must be followed, which functions as an order or a command.

This is a casual and friendly way to invite someone to a social event. The question form is used to offer a choice to the recipient.

The phrase 'is not permitted' explicitly forbids an action, making it a clear prohibition or a rule against doing something.

The phrase 'Would you mind' is a standard polite construction used to make a request for a small favour.

The use of 'Perhaps we could' introduces a potential course of action for consideration, which is the key characteristic of a suggestion.

The structure 'You are to...' is a formal and direct way of giving a command or an order that must be obeyed, typically used by someone in authority.

The sentence provides details of a social event and uses the phrase 'we'd be delighted if you could make it' to extend a warm and clear invitation.

The phrase 'I’d appreciate it if...' is a polite and indirect way of asking someone to do something, which makes it a request rather than a direct order.

This sentence uses the imperative 'Do not' to clearly forbid a specific action for safety reasons, functioning as a strict prohibition or warning.