Although rules of grammar may be a distant memory for many lawyers, the rules of grammar can be important to statutory construction.
Nevada Revised Statutes (NRS) Section 0.025(1) establishes specific rules for the interpretation of statutes using "may", "must", "shall" and "is entitled". Thus, "'must' expresses a requirement when: (1) the subject is a thing, whether the verb is active or passive; or (2) the subject is a natural person and (a) the verb is in the passive voice; or (b) only a condition precedent and not a duty is imposed." Understanding this rule requires an understanding of the voices of verbs.
In English, a verb is in the active voice when the subject of the verb is doing the acting (e.g., "The jury returned a verdict."). A verb is in the passive voice when the subject is being acted upon (e.g., "The jury was instructed by the judge.").
Here's an example from Bishop & Zucker on Nevada Corporations and Limited Liability Companies:
NRS 78.115 provides: “The business of every corporation must be managed under the direction of a board of directors ….” Because the subject of the provision, the business, is a thing, the use of the word “must” in the statute expresses a requirement even though the verb, “managed,” is in the passive voice. NRS 78.330(1) provides “directors of every corporation must be elected at the annual meeting ….” Because the subject of the sentence is natural persons and the verb, “elected,” is in the passive voice, the statute expresses a requirement.
Professor Anita Krishnakumar has even made a study of the United States Supreme Court's references to the passive voice. In Passive-Voice References in Statutory Interpretation, 76 Brooklyn L.Rev. 941 (2011), she argues that "the Supreme Court’s framing of passive-voice arguments suggests both legitimating and harmonizing roles for grammar references in statutory interpretation".