Correct Modal Verbs

Use modal verbs to express ideas such as ability, uncertainty, necessity and permission.

• Can — relates to present ability and general possibility.
• Could — relates to possibility and suggestion.
• May — relates to probability and permission. It also means that an item is optional.
• Need — relates to the absence of obligation. In technical documentation, this verb is used only as a synonym for the verb want.
• Must — relates to personal obligation. It means that the definition is an absolute requirement of the specification.
• Must not —  relates to the absence of personal obligation. It means that the definition is an absolute prohibition of the specification.
• Have to — relates to impersonal obligation. Do not use it as a synonym for the verb must.
• Should — relates to expectation and recommendation. Do not use it as a synonym for the verb must.

To learn more about key words used to indicate requirement levels, see RFC 2119.

Examples

1. Orchestration plans can be scheduled and chained to execute in sequence. [general possibility]
2. By design, you cannot customize the default template itself. [present ability]
3. A situation where you attempt to monitor too many vSphere hosts and VMs could overload the Ops Mgr Health Service and thus result in unstable operation and possible monitoring outage. [possibility]
4. You may need to add new VM groups or remove some groups from an orchestration plan. [probability]
5. If you need to monitor the state of a specific service, you can create and customize a vSphere Host Service Monitor. [want]
6. To create orchestration plans, you must first categorize VMs into VM groups to be used in these plans. [personal obligation]
7. At the Resource Usage step, specify the datastore capacity level that must not be breached during the recovery process for orchestration plans to complete successfully. [prohibition]
8. You do not have to select every single monitor or rule. Just select the object that the monitors run against. [impersonal obligation]
9. The Default Backup Restore IAM role should be created automatically after you perform these steps. [expectation]