Must I? Should you? They might.
Modal verbs, although commonly used, are some of the most grammatically complex parts of the language. They are used to modify the strength or mood of other verbs—in some cases, the differences are subtle but important. There are many modal verbs (can, will, could, would, should, shall, must, may, might), but the two most problematic modal verbs are “should” and “may“.
“Should” has three meanings (encouragement, recommendation or expectation) and is often used (incorrectly) when the writer’s intention should [expectation] be “must“. Writers often use “should” when “must” is required over a misplaced fear of causing offence. Trust me, you aren’t doing the reader any favours by trading politeness with ambiguity.
“May” also has three meanings (ability, possibility or permission) and is another common cause of ambiguity. If used for anything other than permission, “may” should [recommendation] be replaced by “can” or “might“, depending on the intended meaning (see below). My personal choice is to never use “may” in a technical document because there is always a better word available to describe my meaning.
Both words appear frequently in legal documents, often without definition. But just because they appear in a regulation or agreement, it doesn’t mean you should [recommendation] use them in technical documents. The main consideration for technical writers is to ensure that meaning is derived directly from the words you use rather than their context. If you leave it to contextual interpretation, you are just opening the door to misreading and ambiguity.
The recommended usage is (just one meaning per word even though some are multi-meaning):
- can = ability
- could = potential
- may = permission
- might = possibility
- must = necessity
- should = recommendation
- will = intention
- would = conditionality
The applicant submits… (no modal verb) a statement of fact or an instruction
The applicant can submit… the applicant is able to submit
The applicant could submit… the applicant can but has choices
The applicant may submit… the applicant is allowed (by an authority) to
The applicant might submit… but might not
The applicant must submit… statement of necessity or compliance
The applicant should submit… the applicant is encouraged to submit
The applicant will then submit… sometime in the future
If …, the applicant would submit… always preceded with “if”
If you a writing a compliance document, such as a code of practice or a protocol, define these words early in your Definitions section. Your audience will thank you for making their task easier.
Then search through your document and review how each word has been used. In particular, watch for when “may” (the applicant may…) is used as “ability” (change to “can“) or “possibility” (change to “might“) and whether “should” (the applicant should…) needs to be changed to “must“.
may[might] have noticed that “shall” is missing from the list. That’s because it’s considered archaic and is disappearing from modern use. Either change to “must” or a more appropriate modal verb (“can” or “will“, perhaps) or use a strong verb (the applicant is required to…).
Style Guide: modal verbs
October 16, 2015 / Tim McAuley / 0