Yann LeCun‘s evaluation of political versus linguistic errors:

His comment is no doubt meant as a joke, but it’s worth exploring the usage that bothers him.

To start with, the English word plummet has already been on a long morpho-syntactic and semantic journey (like nearly all other words). It started as a noun in Old French, plommet, the diminutive of plom “lead”, meaning “ball of lead, plumb bob“, referring to a (typically lead) weight attached to a “plumb line”. Wikipedia tells us that

The instrument has been used since at least the time of ancient Egypt to ensure that constructions are “plumb”, or vertical. It is also used in surveying, to establish the nadir (opposite of zenith) with respect to gravity of a point in space.

And also, used by sailors to estimate the depth of water.

The noun plummet, under various spellings, was borrowed into English as early the 14th century, and of course was also used metaphorically, as in this example from Shackerley Marmion’s 1632 play Hollands Leaguer:

And when I haue done, I’de faine see all your Artists,
Your Polititians with their Instruments
And Plummets of wit, sound the depth of mee.

And as always, the metaphorical extension got looser, to the point that the noun plummet came to be used to mean simply a “rapid fall” — though this usage seems to be relatively recent, with the OED’s first citation from 1957:

1957 After his plummet from fame, Keaton became a writer. Atchison (Kansas) Daily Globe

Also, like many other English nouns, plummet was soon used as a verb — though interestingly, the OED tells us that the first uses were transitive, connected to the depth-sounding sense of the noun:

1620 This ought to be the barre, cancell and limit of our too scrutinous nature, which often will assay to plummet the fathomlesse and bottomlesse sea of Gods most secret and hidden actions. T. Walkington, Rabboni

The (now more common) intransitive use, meaning (literally or figuratively) “To drop or fall rapidly or precipitously”, came a couple of hundred years later, with the OED’s first citation from 1845:

1845 Our capacity for delight plummeted. N. P. Willis, Dashes at Life with Free Pencil

OK, so what about the usage that bothered Yann LeCun:

In just 52 days, Trump has started a global trade war, plummeted the stock market, fired thousands of federal workers, slashed government funding, and sparked fears of a recession.

The author of that sentence has evolved plummet following the pattern of (the English version of) the causative-inchoative alternation:

The Causative/Inchoative alternation involves pairs of verbs, one of which is causative and the other non-causative syntactically and semantically (e.g., John broke the window vs. The window broke). In its causative use, an alternating verb is used transitively and understood as externally caused. When used non-causatively, the verb is intransitive and interpreted as spontaneous.

(Note that inchoative in this context means something like “change of state”, applied to the intransitive subject; and in the (transitive) causative version, the subject causes the object to the undergo the state change.)

There are many English verbs exhibiting this alternation — boil, melt, sink, open, bake, bounce, blacken, hang, close, cook, cool, dry, freeze, move, open, roll, rotate, spin, twist, shatter, thaw, thicken, whiten, widen, march, jump, …

And it’s common in English to extend this pattern to create a causative transitive verb from an intransitive inchoative one, as I did with evolve in an earlier sentence (though others have done this before me…).

But attempts at such extension don’t always go smoothly, and plummet is not the only example of possible failure. Thus fall is an intransitive inchoative verb, but “*Those actions are going to fall the market” doesn’t work. Why?

This post is already too long, so for now I’ll just direct you to Beth Levin and Malka Rapaport Hovav, “A preliminary analysis of causative verbs in English“, Lingua 1994:

This paper investigates the phenomena that come under the label ‘causative alternation’ in English, as illustrated in the transitive and intransitive sentence pair Antonia broke the vase / The vase broke. Central to our analysis is a distinction between verbs which are inherently monadic and verbs which are inherently dyadic. Given this distinction, much of the relevant data is explained by distinguishing two processes that give rise to causative alternation verbs. The first, and by far more pervasive process, forms lexical detransitive verbs from certain transitive verbs with a causative meaning. The second process, which is more restricted in its scope, results in the existence of causative transitive verbs related to some intransitive verbs. Finally, this study provides further insight into the semantic underpinnings of the Unaccusativity Hypothesis (Perlmutter 1978).

Among other things, they note the difference between “verbs of manner of motion such as roll, run, jog, and bounce“, which have causative counterparts, and “verbs of directed motion such as come, go, rise, and fall“, which don’t. You can read the paper to learn their theory of why this matters — but we can note that the intransitive verb plummet is arguably in between those categories, interpretable either way.

None of the dictionaries that I’ve checked have a causative-transitive sense for plummet = “cause to fall rapidly”, and I don’t think I’ve ever heard or read it — but it wouldn’t be a shock to find other examples, and it’s also understandable that it would trigger someone’s “wrong!” reaction.

A reader has asked for a post on the difference between “mustn’t have + past participle” and “couldn’t have + past participle.” He gives these examples:

a) Ahmed failed the exam. He mustn’t have studied hard.
b) Ahmed failed the exam. He couldn’t have studied hard.

Before writing to me, the reader queried native English speakers of his acquaintance and received these answers.

• Some native speakers say that ONLY the first example is correct.
• Others say that both are correct.
• Some say that “mustn’t have + pp” indicates a conclusion based on evidence.
• Some say that “mustn’t have” suggests an 80% certainty, whereas “couldn’t have” provides 100% certainty.

Both a) and b) are correct.

The first statement is more likely to be spoken by a speaker of British English and the second by a speaker of US English. Either way, in this context, the speakers are merely speculating as to why Ahmed may have failed the exam. In this context, the constructions with mustn’t and couldn’t are interchangeable.

I have found numerous discussions of the mustn’t/couldn’t dichotomy in ESL forums. I don’t think I’d ever seen percentages of certainty applied to grammatical constructions before.

Degrees of certainty
Here is an illustration from an actual grammar book:

In answer to the question “Why didn’t Sam eat?”:

“Sam wasn’t hungry.” (The speaker is 100% sure that this is the reason.)

“Sam can’t have been hungry.” (The speaker believes – is 99% certain –that it is impossible for Sam to have been hungry.)

Sam must not have been hungry. (The speaker is making a logical conclusion. We can say he’s about 95% certain.)

“Sam might not have been hungry.” (The speaker is less than 50% certain, and is mentioning one possibility.)

Rather than assigning percentages of certainty to these constructions, it makes more sense to me to say that sometimes they convey certainty and sometimes they don’t. It all depends on context.

Here are examples in which mustn’t have and couldn’t have do indicate a conclusion based on evidence.

If the blood was still fresh that meant this murder mustn’t have been too long ago.

From the style of his writing he mustn’t be older than 30 years of age.

The car’s windows are darkly tinted, so Snell couldn’t have seen Johnson inside.

She couldn’t have understood the radio broadcast because she does not speak Dutch.

The evidence for the conclusion lies in the sentence itself.

the freshness of the blood.

the writing style.

the windows were too dark to see through.

the listener did not know the language.

Other contexts
Lacking internal evidence, the application of percentages to the “certainty” of the meaning of these two constructions is an exercise in futility.

The following examples can convey ideas other than certainty.

You mustn’t have spent much time in New York. (sarcasm?)

He mustn’t have finished his homework on time. (Maybe he didn’t do it at all)

She couldn’t have tried very hard. (Maybe she tried as hard as she could, but lacked the necessary ability.)

Q: Am I showing my age? Once upon a time, a couple of decades ago, when you were ill or had an emergency, you would “call in sick.” Now it’s “calling out.” When did that happen?

A: People have been calling “in,” “out,” and “off” sick for dozens of years, but “call in sick” is the oldest and by far the most common expression for reporting one’s absence from work because of illness.

The Oxford English Dictionary defines “call in sick” as “to contact one’s employer, school, etc., typically by telephone, to report one’s absence that day, esp. due to illness.” The OED’s earliest example is from the 1940s:

“This being a holiday weekend, employees in Treasury’s loans and currency section … were warned yesterday not to call in sick either today or Monday under any circumstances” (The Washington Post, July 3, 1943).

The dictionary’s first citation for “call off sick” is from a West Virginia newspaper: “Personnel who frequently call off sick … should be checked at their homes to ascertain the legitimacy of their absence” (Charleston Daily Mail, May 24, 1958).

The earliest OED example for “call out sick” is from a Massachusetts newspaper: “Bray said no one called out sick in the DPW at all this week … [due] to his demands that anyone out sick must have a doctor to certify illness” (Sentinel & Enterprise, Fitchburg, April 16, 1976).

A similar expression, “call off work,” has been around since the the mid-1960s and means “to report one’s absence from (work, school, etc.), typically by making a telephone call,” Oxford says.

The dictionary’s first citation is from a 1965 labor arbitration decision: “He would receive a final warning if he didn’t improve on the tardiness, absenteeism, and calling off work without notice” (from Labor Arbitration Awards, Vol. 65-2).

A search with Google’s Ngram Viewer, which compares words and phrases in digitized books, indicates that “call in sick” is clearly the most common of the four expressions.

We’ve seen suggestions online that “call out sick” may be especially popular in New York, New Jersey, and Connecticut, but we’ve seen no linguistic evidence to support this. The Dictionary of American Regional English doesn’t mention the usage.

The 2025 slate of Oscar nominees recognizes many writers, directors and actors whose scripts and performances don’t necessarily reflect their own cultural and linguistic backgrounds.

Greg Kwedar and Clint Bentley, both white, co-wrote “Sing Sing,” a story about rehabilitation through art in a maximum security prison where the characters are almost entirely people of color.

Meg LeFauve has now earned her second nomination for penning a script that gives voice the gamut of emotions surging through a young girl in “Inside Out 2.” She’s in her 50s.

The director of “Conclave,” Edward Berger, its writer, Peter Straughan, and its lead actor, Ralph Fiennes, are all self-proclaimed lapsed Catholics. Yet they brought to life a political thriller set in the Vatican.

“The Brutalist” was written entirely in English, but much of the film’s dialogue is in Hungarian, with two leads who are not native Hungarian speakers.

Most screenwriters endeavor to craft characters outside their own backgrounds and experiences. But concerns about authentic language representation and cultural accuracy persist, and accusations of cultural appropriation and lazy research are commonplace.

“Emilia Pérez,” for example, has been heavily criticized not only for unrealistic portrayals of gender transition but also for inauthentic depictions of Mexican culture and accents.

We surveyed over 50 current members of the Writers Guild of America, and they broadly told us that sensitivity to linguistic representation has increased since the 2010s.

Several commented that there’s been more commitment to hiring writers who represent the characters’ voices and backgrounds. There’s also more “freedom to include diverse characters and worlds… but a commensurate emphasis on authenticity and a higher bar for what that means,” as one writer explained.

“Authenticity” was consistently cited in our survey as a principal consideration when writing dialogue. Other concerns included scripts’ intelligibility, historical accuracy and believability.

In our study, we also reviewed screenwriting manuals published as far back as 1946.

Manuals didn’t begin to raise explicit ethical concerns, such as the use of inaccurate linguistic stereotypes in dialogue, until the 1980s. For example, many older films, such as “Gone with the Wind,” often used phonetic spelling in their scripts, with features such as g-dropping – “quittin’” for “quitting” – to mark only the speech of lower-class or racially marginalized characters, despite the fact that all people, regardless of background, have accents.

In fact, limiting oneself to standard U.S. English restricts diversity in the written dialogue itself. Some writers may want to use dialect or language to convey character authenticity on the page.

Our survey respondents described this as “flavor” – the strategic use of dialectal words or phrases to create distinct voices, with limited phonetics. Jesse Eisenberg, in his Oscar-nominated script “A Real Pain,” lightly blends American English with occasional Yiddish words to great effect: “… landed in Galveston for some fakakta reason,” or “crazy” reason.

AI chimes in

Attempts at authenticity can become muddied when AI gets involved.

When making “The Brutalist,” Corbet controversially used AI technology to refine the movie’s Hungarian dialogue.

Some questioned the film’s authenticity due to the use of AI, arguing that nothing can be authentic if it’s achieved artificially.

But the film’s creators, including editor and native Hungarian speaker Dávid Jancsó, defended this choice. They argued the technology actually enhanced the language’s authenticity, particularly since Hungarian’s system of vowels and consonants is especially hard for nonnative speakers to capture accurately.

Whether writers use phonetics or standard language, and whether producers use AI or dialect coaches, questions of ethics and linguistic authenticity will remain. It’s important to research language choices and dialogue, and to consult the diverse speakers portrayed in scripts.

These are among the many essential checks and balances that are becoming bigger parts of the filmmaking process.

The article by Sharmila Kuthunur highlights a subtle change that might have gone unnoticed but underscores how easily history can be rewritten—especially when it’s written in code rather than in stone.

The recent alteration of Vera Rubin’s biography in the Rubin Observatory’s website serves as a stark reminder of the broader need to capture and preserve oral histories before they can be rewritten or erased. Oral histories provide an unfiltered record of lived experiences. When governments or institutions attempt to reshape narratives for political purposes, these firsthand accounts become even more valuable as a safeguard against revisionism. By transcribing and archiving oral histories, we ensure that diverse voices and untold stories remain protected, accessible, and truthful for future generations.

Astronomers are expressing disappointment and alarm as the federally-funded Rubin Observatory altered the biography of renowned astronomer Vera Rubin, for whom the facility is named, on its website. The amended version curtails her legacy of championing women in science and removes all mentions of the observatory’s efforts to reduce barriers for women and other historically underrepresented groups in the field.

“No executive order, no political edict is going to undermine or end our efforts to make the scientific workforce look more like our people,” astronomer John Barentine told Space.com. “If anything, it is giving us more encouragement to continue to do this work, because it is the morally, philosophically and politically right thing to do.”

The edits, first reported by ProPublica on Jan. 30, came as federal agencies across the government scramble to revamp their websites in order to comply with a U.S. executive order issued by President Donald Trump, which ends funding for diversity, equity, and inclusion (DEI) efforts and removes all mentions of them from public-facing websites.

On Jan. 27, a portion of Rubin’s bio titled “She advocated for women in science” was removed entirely before being republished later that day in a diluted form, ProPublica reported. As of publication of this story Tuesday (Feb. 11), the altered bio still excludes a paragraph that originally read: “Science is still a male-dominated field, but Rubin Observatory is working to increase participation from women and other people who have historically been excluded from science. Rubin Observatory welcomes everyone who wants to contribute to science, and takes steps to lower or eliminate barriers that exclude those with less privilege.”

One sentence in the final paragraph, which originally read, “Vera Rubin offers an excellent example of what can happen when more minds participate in science,” was changed to replace “more” with “many,” altering the meaning from emphasizing the need for diverse perspectives to simply highlighting a high number of people.

“This is the story of what happened in her life,” Yvette Cendes, a radio astronomer at the University of Oregon, told Space.com. “She was a huge champion for women in science in particular because she faced things that were discriminatory for women — diminishing those stories is pretty disturbing, frankly.”

Other pages on the observatory’s website, including the jobs and staff bio pages, have also been modified to erase mentions of diversity and inclusion efforts. The Observatory, its funder, the National Science Foundation, and the White House did not respond to Space.com’s request for comment on Feb. 3.

Rubin earned worldwide recognition for changing the way we think of the universe by showing that galaxies are mostly composed of dark matter, the mysterious, invisible substance that makes up much of the cosmos. Her research provided crucial evidence for dark matter’s existence through observations of stars in our neighboring galaxy Andromeda, where she found that stars moved at the same rate regardless of their position — an indication of “missing” mass, which she proposed could be explained by dark matter. Her findings shifted scientific consensus toward accepting dark matter as a fundamental component of the universe, opening new realms in astronomy and physics.

Beyond her scientific achievements, Rubin also paved the way for women in science. Perhaps most notably, in 1964, she battled to gain access to observe at the famed Palomar Observatory in California, becoming the first woman officially allowed to use its telescopes. Colleagues recall that when Rubin noticed the only restroom at the observatory was labeled “MEN,” she cut out a tiny paper skirt and taped it to the image of a man on the door. “She turned around and said, ‘Now you have a ladies’ room’ and then she got to work — that was Vera Rubin,” reads a 2021 statement from former Carnegie Science President Eric Isaacs.

Throughout her career, she championed women in the field. As one example, “she frequently would see the list of speakers [at a conference],” former colleague Neta Bahcall of Princeton University told Astronomy.com, “and if there were very few or no women speakers, she would contact [the organizers] and tell them they have a problem and need to fix it.”

“But what if she hadn’t been that fierce? What if she hadn’t been the personality that we have all come to know — the unstoppable warrior?” Isaacs said in the Carnegie Science statement. “And here’s the question that really haunts me, which is how many Vera Rubins have we lost to these kinds of obstacles?”

As similar barriers are threatening to resurface due to the Trump administration’s ongoing efforts to erase initiatives aimed at improving diversity in science, the astronomy community seems to be remaining steadfast in its refusal to reverse decades of progress.

“Astronomy is not going to let Vera’s contributions be forgotten,” said Barentine. Various groups are actively working to use tools to archive content that has already been removed, as well as content that could potentially be erased from federal websites.

“The idea that they can somehow obliterate these sources is dead wrong — scientists in general and astronomers in particular are not going to take these threats lying down,” he said. “But we have a long road ahead and I expect there’ll be times when that road will be very difficult to walk.”

He declined to disclose the specifics of these efforts, but noted that “the forces aligned against this should be aware that it’s happening, and they won’t be able to stop it.”

Even at NASA, offices associated with DEI initiatives were shut down during Trump’s first few days in office. A recently instated, high-profile program called Here to Observe (H2O), which paired undergraduate students from underrepresented groups with scientists running NASA missions, was recently grounded. The media outlet 404, an independent journalist-founded news website, reported that NASA employees were told to “drop everything” and “scrub mentions” of a list of words from public-facing sites, including “Indigenous People,” “Equity,” “Accessibility,” “Environmental Justice” as well as “Anything specifically targeting women (women in leadership, etc.).” NASA has since removed “inclusion” as one of its core values.

The flurry of changes triggered by the directive has led to the erasure of articles featuring NASA astronomers from underrepresented communities that the agency published in years past, like this one. Now, these pages sometimes display launch schedules of past SpaceX launches instead of the original prose. The original titles appear to remain. Agency employees have also been instructed to remove their pronouns from all work communications and instead follow a pre-designed signature block adopted by the agency, NPR reported.

Astrobiologist Michaela Musilova, who served as the Director of the HI-SEAS space research station in Hawaii, told Space.com that her efforts to encourage more women, people of color and LGBTQ+ scientists to join her simulated missions to the moon and Mars resulted in more applicants from these communities.

“Representation matters — some of them told me that they only applied because they saw that others like them were successful in this sector too,” she said. During those simulated missions, “the more diverse a crew was, the more successful a mission ended up being — the team got along better, was able to problem solve more efficiently and they were also more productive with their research projects.”

The impacts of the ongoing changes, which have prompted many talented and experienced people to leave the space agency, “will likely be long-term and they could cause many interesting projects to not get pursued or finished,” she said.

On May 17, 1996 — nearly 50 years after her own graduation in 1948 — Rubin addressed the graduating class at the University of California, Berkeley, saying: “I hope that you will fight injustice and discrimination in all its guises. I hope you will value diversity among your friends, among your colleagues, and, unlike some of your regents, among the student body population.”

“I hope that when you are in charge, you will do better than my generation has.”

Generally speaking, a particle is a word that doesn’t belong to the usual classes of words like noun, verb, pronoun, etc.

Authorities disagree as to which words to call “particles,” but most agree that the to of an infinitive and the words that look like adverbs or prepositions in a phrasal verb are particles. Compare:

The family traveled to Paris. (preposition governing the noun Paris.)
Now they are ready to go home. (particle, part of the infinitive “to go.”)

Jack and Jill went up the hill. (preposition governing hill)
Mr. Abrams will set up the conference room for the next meeting. (particle, part of the phrasal verb “set up.”)

The particle most likely to cause difficulty for the non-native speaker is the “adverbial particle” used to create a phrasal verb.

A phrasal verb is “a fixed combination of verb and adverbial particle” used in many colloquial and idiomatic expressions.

Phrasal verbs present difficulties for non-native speakers because their meaning is difficult or impossible to guess from the individual words that make them up. For example:

His son said that he was ready to turn in.

Where were you when the meeting broke up?

Some phrasal verbs have different meanings, according to context. For example:

put out
He put out the light and went to bed. (“extinguish” in the sense of interrupting an electric current)
The firemen put out the fire. (“extinguish” in the sense of smothering flames)
Don’t forget to put out the cat before you leave the house. (“place outside”)

pass out
The heat caused the girl to pass out. (faint)
The lecturer asked me to pass out the papers. (distribute)

turn up
Turn up the radio so I can hear it. (increase the volume)
I didn’t expect you to turn up here. (appear)

add up
Her behavior this morning doesn’t add up. (make sense)
She waits until she gets home to add up her tips. (count)

break down
He’s likely to break down on the witness stand. (become emotionally upset)
The CEO asked the accountant to break down the quarterly figures. (analyze)

fill in
Be sure to fill in every blank on the second page. (complete)
The boss asked me to fill in for her at the summit meeting. (substitute)

Sometimes the particle is separated from the verb by another word:

He took his boots off before entering the house. (removed)
They called the doctor in when the child’s fever increased. (summoned)

Writers targeting non-native speakers may want to pay special attention to phrasal verbs when revising, either to replace a phrasal verb with a simple one-word substitute or to avoid using the same phrasal verb with different meanings in the same document.

Phrasal verbs easily replaced by one word
throw away: discard
send back: return
pull through: recover
put off: postpone
call off: cancel
cut down on: reduce
put up with: tolerate

Are you ready to test your knowledge? Here’s a fun little quiz!

Exercise – Smothered Verbs

Each of the following sentences includes a smothered verb (i.e., a word that has been formed from a verb). Revise the sentences as necessary for conciseness:

1. The committee will hold a meeting this Wednesday evening at seven o’clock.

2. I will make a decision after studying the criteria you have given me.

3. We hope someone can provide an answer to this political question.

4. A school counselor’s job is to give advice to the students.

5. Please take into consideration the suggestion your father made.

Answers and Explanations

In order to improve sentences containing smothered verbs you simply need to replace them with the original verbs. Example: Her guardian has made provision for her in his will. You should replace “has made provision” with “provided.”

1.
Original: The committee will hold a meeting this Wednesday evening at seven o’clock.
Correct : The committee will meet this Wednesday evening at seven o’clock.

2.
Original: I will make a decision after studying the criteria you have given me.
Correct : I will decide after studying the criteria you have given me.

3.
Original: We hope someone can provide an answer to this political question.
Correct : We hope someone can answer this political question.

4.
Original: A school counselor’s job is to give advice to the students.
Correct : A school counselor’s job is to advise the students.

5.
Original: Please take into consideration the suggestion your father made.
Correct : Please consider the suggestion your father made.