EDUCE Overview Copyright 2009 Nikolas S. Boyd.
All rights reserved.

Normal Mood


Convert verbs to the indicative mood, unless the verb describes an optional (potential) behavior.


Verbs can express an action or state as an actual fact, or the potential for such. The moods include indicative, subjunctive, potential, imperative, infinitive. Some examples include:

strive lest you fail (subjunctive)
to sympathize is to understand (infinitive)
a cat may eat a mouse (potential)
a cat will eat a mouse (imperative)
a cat eats a mouse (indicative)


Use indicative mood when


A predicate with subjunctive mood indicates a state (or event) supposed or imagined, or contingent or contrary to the fact. The indicative mood serves equally well to express these modes. So, usage of the subjunctive mood has virtually disappeared from English. If you find a statement with the subjunctive mood, rephrase it using the indicative mood or the imperative mood with affirmative polarity. Consider the following rephrasing of the former subjunctive example.

you will succeed if you strive

A predicate with potential mood indicates a possible or probable (or necessary) state (or event). Some consider these to be variations of contingency, and therefore subjunctive. However, they differ in the explicit use of auxiliaries such as can, may, could, might, must, should, would. If you find a problem or solution has an optional feature, retain the potential mood. However, for clarity sake, you should also indicate this point of variation or optionality explicitly in a requirements specification.

A predicate with infinitive mood has no subject, and so has no limitations of person or number. A verb with infinitive mood is often used to express a purpose, an objective, or a goal. The infinitive mood is especially useful for expressing the quality concerns of business stakeholders. Consider the following examples:

to ensure safety compliance
to minimize depot vulnerability

A predicate with imperative mood issues a command or permission, or indicates a wish, thereby describing an event to bring about a desired state. A predicate with indicative mood indicates a real or factual state (or event). The imperative and indicative moods complement each other, and they are both useful in relation to object-oriented designs. A verb with indicative mood is often used to describe object responsibilities while a verb with imperative mood is often used as a prefix in object method names.

It's interesting to note that many programming languages are considered imperative (as opposed to declarative). These imperative programming languages usually include reserved words such as if, then, else, do, goto. The imperative mood is the traditional way in which software requirements are phrased. However, for the purpose of conceptual models and object-oriented models, which are fact-oriented, the indicative mood is preferable.


A normal form sentence has an indicative verb with a complete predicate, singular number, active voice, affirmative polarity, and appropriate tense.