Word classes

How many words are in the English language?

That seems like it should be a relatively easy question to answer – just check a big dictionary, or ask chat GPT, right? Well, The Oxford English Dictionary (a super famous and detailed one, available online) has over 600,000 entries. That includes lots of old words that aren't used anymore. But even that huge number isn't the full story, and we can never get an exact count of every word in English today.

Why not? Why can’t we get an exact count of every word in English today?

English is always changing – and super fast! Brand-new words pop up all the time (like tech words, slang, or words from other languages). Old words disappear or get forgotten. Words can get new meanings (e.g., "sick" used to mostly mean ill, but now people say "that's sick!" to mean awesome or cool). People make up words just for one moment (called nonce words), or create fun new combinations (yarn bomb, bloatware). Some words are super specific to science, medicine, or certain jobs — do we count those as normal English words? English varies a lot around the world (British vs. American vs. Australian, etc.), so what's common in one place might be rare somewhere else.

Because of all this constant change, no dictionary can ever catch everything perfectly. It's like trying to count all the leaves on a tree while new ones grow and old ones fall off every second. But there's a smarter way to think about the question — by grouping words into two big types or classes.

Consider the random list of words below

Pig, autumn, explain, they, which, sing, suddenly, from, today, biology, and, truth, could, the, extraordinary, since, hot, announce, in.

Most native English speakers naturally split them into two groups without even thinking hard:

Group 1 (the bigger, more interesting words):

• Pig, autumn, explain, sing, suddenly, today, biology, truth, extraordinary, hot, announce

These feel more "real" or full of meaning. You can picture them easily (a hot pig? An extraordinary autumn?). They're usually longer, and you can even string some together and get a vague idea (like "hot pig announce truth" – weird, but sort of makes sense).

Group 2 (the short, helper words):

• They, which, from, and, could, the, since, in.

These don't mean much on their own. You can't really picture "the" or "and" by themselves. You need them to connect or support the other words, but they're tiny and boring by comparison.

These two groups have official names

Group 1: open class words (also called lexical words or content words).

They include:

-       Nouns (pig, autumn, biology, truth)

-       Verbs (explain, sing, announce)

-       Adjectives (extraordinary, hot)

-       Adverbs (suddenly, today — "today" can act like one)

Tip: just remember NVAA. (N)ouns, (V)erbs, (A)djectives, (A)dverbs

But why are the called the open class?

These groups are like open doors – English happily adds new words to them all the time. New nouns, verbs, adjectives, and adverbs enter the language constantly. That's why there are hundreds of thousands of them. They're huge and always growing!

Group 2: closed class words (also called grammatical words or function words).

-       Pronouns (me, they, which)

-       Determiners (the)

-       Auxiliaries (could)

-       Prepositions (from, in)

-       Conjunctions (and, since)

Tip: just remember, P. DAP. C. (P)ronouns, (d)eterminers, (a)uxiliaries, (p)repositions, (c)onjunctions

Why is group two called the closed class of words?

These groups are like locked doors – new words almost never get added. The list stays small (only a few hundred words total), and it changes very, very slowly. Most of these little helper words come from very old English (or Viking influences from long ago).

Quick differences to remember:

Open-class words carry most of the meaning, can be long/complex, there’s lots of them, they change/grow a lot, many come from other languages over history.

Closed-class words are short and simple (usually 1-2 syllables), super common (we use ‘the’ or ‘and’ in almost every sentence!), but we don't stress them much when speaking, almost all closed class words come from very old English roots.

In summary

The best simple answer to “How many words in English?" is:

The open classes (nouns, verbs, adjectives, adverbs) have hundreds of thousands of words and it’s probably impossible to count them all exactly because they're always changing and growing.

The closed classes (pronouns, determiners, auxiliaries, prepositions, conjunctions) have only several hundred words which are small, stable, and possible to list almost completely.

That's why we say English has a massive, ever-changing vocabulary, but the ‘glue’ words that hold sentences together are few and pretty fixed.