A misplaced modifier could cause readers to misunderstand your blog post, and a poorly-punctuated résumé could lose you a potential job interview, so it’s important to think about the relationship between what you write and what you mean, especially the grammar and wording. That said, minor linguistic errors or ambiguities don’t usually lead to any earth-shattering consequences.

Sometimes, though, they do. The following are three situations in which the nitty-gritty details of grammar and wording and/or punctuation had some major real-world impacts.

A Missing Comma Costs a Company Millions

The Oxford comma is used to separate the penultimate item in a series from and or, as in the following sentence: “I love my parents, Harry Potter, and Beyoncé.”

Guidelines on whether to use the Oxford comma vary, and people have heated debates about its usage. But one stands out as the hottest: a recent lawsuit between a Maine-based dairy company and its delivery drivers.

Maine law states that the following activities do not entitle workers to overtime pay:

“The canning, processing, preserving, freezing, drying, marketing, storing, packing for shipment or distribution of:

(1) Agricultural produce;
(2) Meat and fish products; and
(3) Perishable foods.”

See how between “packing for shipment” and “or distribution,” there’s no comma? The drivers argued that due to the absence of a comma. That part of the sentence means this: you earn no overtime pay if you pack for either the shipment or the distribution of the specified products.

According to this interpretation, the sentence says nothing about distribution itself. Since the drivers distribute, but do not pack for distribution, they argued that their work technically qualified for overtime pay.

The company claimed that the sentence meant “packaging for shipment” and “distribution” as two separate activities. Which led to this interpretation: you earn no overtime pay if you either pack for shipment or distribute the specified products.

The court decided in favor of the drivers, saying that the lack of comma makes the meaning unclear and that, under state law, this ambiguity meant that the company had to pay overtime.

This decision could cost the dairy company $10 million. That’s a steep price to pay for one little punctuation mark.

Billions of Dollars at Stake over a Definition

The financial stakes can be even higher in a lawsuit following the September 11, 2001 terrorist attacks on the United States.

A few weeks before September 11, businessman Larry Silverstein became the leaseholder for the World Trade Center site. He had multiple insurance policies worth a total of $3.55 billion dollars per catastrophic “occurrence.”

After the towers were destroyed, Silverstein argued that he should receive about $7.1 billion in insurance money. He said two separate occurrences had destroyed the World Trade Center. The attack on the first tower, and the attack on the second one. The insurance companies argued that although there had been two crashes, they had been part of a single coordinated attack. They were components of one occurrence.

The court eventually determined that due to the wording and timing of certain legal documents, some insurance companies owed Silverstein the single payout while others owed him the double payout.

As Steven Pinker points out in The Stuff of Thought, the fact that literally billions of dollars were at stake over the definition of occurrence highlights the importance of precise wording.

A Major Plane Crash

Sadly, the consequences of imprecise wording can be more than just financial.

In 1977 at Tenerife Airport, located on one of the Canary Islands, two Boeing 747s collided and killed over 500 people. Multiple factors contributed to this crash. It was foggy, for one, and Tenerife Airport was overcrowded because several planes had been rerouted there.

Miscommunication was part of the problem, too. A major issue came up when a pilot said “We are now at takeoff” and the controller responded, “Okay…stand by for takeoff, I will call you,” Another transmission came through at the same moment, so it seems that all the pilot heard was “Okay.”

Of course, in everyday speech, okay can be an acknowledgment, which is presumably the way the controller meant it. Okay can also be used to express assent, though, and it appears that the pilot interpreted the controller’s “okay” as permission to take off. However, it was not yet safe to do so, and the misinterpretation had deadly consequences.

Sadly, this is not the only case in which imprecise wording contributed to a plane crash. These days there is a standardized English, Aviation English, used internationally in civil aviation. It is designed to avoid ambiguous terms like okay and to ensure that everyone involved understands each other properly.

This plane crash and these two lawsuits are a reminder of how important precise use of grammar and wording can be.