As with the words minimal and minimum discussed in the previous post on troubling pairs, the words optimal and optimum are also often used interchangeably. Indeed, optimal and optimum can also be synonyms, but while optimum can function as both an adjective and a noun, optimal is just used as an adjective.
Unlike minimal and minimum, which date back to the 17th century, optimal and optimum appear only in the 19th century—one source says in the middle (1848) and the other says late in the century. Optimum was invented by scientists who, as merriam-webster.com states, felt the need of a word and “naturally pulled it straight from Latin without changing a thing.” As this dictionary and lexico.com both point out, optimum in Latin “is the neuter of optimus, meaning ‘best.’”
Merriam-webster.com gives the first definition of the noun form as “the amount or degree of something that is most favorable to some end” with this as a sample sentence: The substances were mixed in various proportions until an optimum was reached.
This online dictionary goes on to specify that the word especially relates to “the most favorable condition for the growth and reproduction of an organism”: The soil condition for this crop is now at an optimum.
Lexico.com gives a more inclusive and concise definition as “the most favorable situation or level for growth, reproduction, or success.” Its sample sentence, nevertheless, harks back to the word’s scientific origins: the plant grows within a range of 68 and 78°F, the optimum being 74°.
According to the “Usage Notes” section of merriam-webster.com, “it was only a few decades into the noun’s existence” that optimum “started to be applied as an adjective as well. And at about the very same time, a synonymous and related adjective—optimal—was coined” (1890).
Merriam-webster.com says the use of optimum as an adjective is rare—this could be why many may object to its use in place of optimal, which functions only as an adjective. In fact, this dictionary does not even devote an entry to the adjective form.
Lexico.com, however, does give the adjectival form a listing: “most conducive to a favorable outcome; best”; for example: the optimum childbearing age. Moreover, there are many examples of its adjectival use (more than of the noun) on lexico.com (a project of the Oxford English Dictionary or OED), which might result from the difference in the usage between American and British speakers.
As mentioned above, optimal is only an adjective, and this does get an entry from merriam-webster.com, which ironically gives optimum as part of the meaning: “most desirable or satisfactory: OPTIMUM (emphasis theirs).” Here are two uses of the word: the optimal use of class time and the optimal dosage of medication for a patient.
The “Usage Notes” does bring up the faction that would want to preserve the distinction the two forms offer, using optimum only as a noun and optimal as the adjective. And it notes that there are other pairs that follow this pattern: bacterium/bacterial, cerebrum/cerebral, cranium/cranial, imperium/imperial. According to merriam-webster.com, the adjective form optimal is “the more common choice,” which again may reflect the difference between American usage (which merriam-webster.com records) and the British usage recorded by the OED/lexico.com.
Another pair that gives people trouble consists of the words good and well. According to The American Heritage usage guide, well has been used as both an adjective and as an adverb since Old English times. When describing people, well usually refers to a state of health or the state of one’s well-being. On the other hand, the word good has a “much wider range” and can mean “attractive” (as in She looks good) and “competent” (as in For a beginner, he’s pretty good), in addition to “healthy” (499). The reference work provides this example sentence: George may look good, but he’s not well.
Traditional grammar books usually make the distinction that good is an adjective and well is nearly always an adverb and its only “proper” use as an adjective is when referring to health. For example, one handbook cautions “Do not say ‘I feel good’; say ‘I feel well.’” (Clark and Knox qtd in Shea).
As Ammon Shea elaborates in Bad English, the proscription against using good for well surfaces in the 19th century. However, as he points out, the OED notes the use of good meaning “Of state of mind, courage, spirits: Not depressed or dejected” occurs as early as the 12th century (119). Furthermore, he calls it a “grammatically flawed” rule based on “specious grounds.”
Traditional grammars argue that good is an adjective and words that follow verbs should be adverbs. But English functions in a different, basic way: linking verbs (such as be) can be followed by an adjective, as in “I am irritated” or “You are annoying.” The word feel is also a linking verb, so that phrases such as ‘I feel good’ are acceptable and can refer to health, not just an emotional condition.
The pair bad/badly have been regarded in a similar fashion: the adjective bad can follow the linking verb feel, while the adverb badly must be used with a non-linking (or active) verb. In common discourse, bad is often used as an adverb (The house was shaken up pretty bad or We need water bad) and badly is used as an adjective (I feel badly). These usages have become more and more common in informal speech and often accepted in written formats.
For instance, as American Heritage notes, the use of want badly/need badly, once considered incorrect, is now widespread, even in formal contexts. Consider this excerpt the reference book cites from the published work Ulysses S. Grant by Brooks D. Simpson: “He wanted so badly to be the sort of father who spent time with his boy, walking and riding about—the father he never had” (419). Bryan A. Garner, usually more conservative, agrees that using badly meaning “very greatly” or “very much” is today “perfectly idiomatic, though previously its usage had been criticized.” He provides this example: “Democrats demanded concessions in a bill tightening immigration laws, another measure Republicans want badly.” (81)
As often discussed in this blog, the English language is always changing because people are using it and adapting it to their uses and styles, regardless of proscriptions and prescriptions. Some usage experts like Shea have no patience with people who insist on distinctions that are often not justified by the histories of word usage. Others are reluctant to accept changes, often condemning them – evidence of purism.
However, sometimes usage pronouncements must be seen for what they are – evidence of classism and racism, as in Garner’s assertion that the use of bad as an adjective is “expected” in the statements of professional athletes, but not acceptable in an announcement for symphony function which “should probably be more literate” (81). Institutionalized racism exists in our language and professions as well as in policing and laws, subjects of several previous posts, such as the one on the confederate monuments debate and the one on naming – calling it like it is. These examine the assumptions and prejudices and rhetoric behind much of our culture.
(Resources: merriam-webster.com on optimum and on optimal; lexico.com on optimum and on optimal; merriam-webster.com optimum vs optimal; The American Heritage Guide to Contemporary Usage and Style; Shea, Bad English; Garner’s Modern American Usage.)