Why we send ‘congratulations’ but not ‘congratulation’

Why is congratulations always plural? Constructions like “Congratulation on your promotion!” or “Your team won – congrat!” just sound wrong. This question has a simple answer and a more complicated one. Let’s get into the weeds first.

Some grammarians put congratulations on the list of pluralia tantum, words that occur only in the plural, like belongings, leftovers, and trousers. But while belongings et al. really don’t have singular forms – one would never say “I bought a trouser” – congratulations does, as in the phrase “a typical congratulation takes the form of ...” for example. I would argue that the real issue is whether congratulation(s) is a count noun or a noncount noun. 

Count nouns answer the question “How many?” How many chairs are there? Six chairs; a few chairs. “How much?” elicits a noncount, or mass noun, an undifferentiated quantity or abstract quality. How much sand is at the beach? There’s a lot of sand, never “six” or “a few sands.” Congratulation(s) works in both categories.

Nouns formed with the Latin suffix -tion are often both count and noncount nouns. The suffix takes verb “X” and makes a noun that means “the state or condition of being X’d” – completion is thus the state of being completed, protection the condition of being protected, and so on. These are mass nouns, abstract ideas that don’t make sense to count. The suffix also creates countable nouns that refer to concrete “instantiations” of X, to paraphrase the Oxford English Dictionary. Thus we can have the abstract idea of detention, and also countable detentions. 

Not all -tion words occupy slots in both categories, though, and which nouns are what kind has changed over the years. Starvation is always a mass noun – “much starvation is avoidable,” not “many starvations.” Munitions is almost always a count noun: “the army has many munitions.” Today information is a mass noun, but in the past it was countable too – people frequently conveyed “many informations” as well as “much information” from the 15th through the 19th centuries. English would not have had to develop very differently for “[Much] congratulation on your promotion!” to be the norm.

The English language gives us the tools to craft innumerable ways to convey gratitude, sympathy, sorrow, or happiness over the achievements of others. If you don’t want to think too hard about it, English also has a number of rote formal expressions of feelings: I give you my condolences, my sympathies; thanks; congratulations. 

Why give one congratulation when you could give many!