That Thinking Feeling

Psychology's answers to everyday questions, in blog form!

Why do words get stuck on the tip of my tongue?

Pop quiz! No cheating, now…

What is the capital of Venezuela?
What is the word for a trench left in the ground by a plough?
Who played Molly Weasley in the Harry Potter films?

It’s possible that you can’t remember one these. Maybe you have a sense that you know the answer, you just can’t bring it to mind right now; that it’s stuck on the tip of your tongue, or your finger, if you’re a sign language user [i]. (I’ve stuck with tip-of-the-tongue for now, as there’s much more research on spoken language than signed language in this area).

If you’ve got stuck on an answer and you can’t bear it any longer, I’ve put them at the end. 

A seal poking its tongue out, about to roll off a jetty

A seal poking its tongue out, about to roll off a jetty


This seal is about to remember the word “gravity”


Psychologists have been studying why words get stuck this way since at least the 1930s. Thanks to those decades of research, we know that even if you can’t recall the word you’re trying to find, you can often name the number of syllables it has, the first or last letter, perhaps even the first few letters – the sas of sasquatch, or the cr of cryptozoology [ii]. For some people who have lexical-gustatory synaesthesia (which means that words seem to have tastes), a tip-of-the-tongue word can cause them to experience the taste of the word even if the word itself eludes them [iii].

To understand the theories about why tip-of-the-tongue states happen, we’ll first need to talk about the different kinds of knowledge that people can have about a word. Suppose I’m teaching you a new word. Clepsydra is a good one for this purpose because not many native speakers of English know it – I certainly didn’t until I looked up a list of rare words just now.

You can probably have a good guess at how it’s pronounced, right? This is phonological knowledge about the word.

If I tell you it’s a noun, you now also have some knowledge about where it might go in a sentence – e.g. “I hit the clepsydra” is fine (well, it’s not fine, but it makes grammatical sense), but “I clepsydra the ball” is not. This is syntactic knowledge.

Because clepsydra is a rare word, you probably don’t know what it means, even if you speak the language it comes from, Ancient Greek, because it’s made up of klepstein (“steal”) and hudōr (“water”). Those words don’t really tell you straight out what a clepsydra is: a kind of clock that measures time by the flow of water. Now you know the meaning of the word, which is semantic knowledge.

Schwartz and Metcalfe [iv] have a nice summary of the different theories about tip-of-the-tongue words:

  • Direct-access theory suggests that when tip-of-the-tongue states happen, we’re able to access our semantic knowledge and perhaps syntactic knowledge about the word, but there’s a delay in accessing the phonological knowledge.

  • Metacognitive theory is very similar, only we add in a metacognitive monitor. Metacognition is literally ‘thinking about thinking’ – which you’re doing it right now, since you’re reading about psychology! In the metacognitive theory, the knowledge that you do have about the word you’re trying to find is integrated in this metacognitive monitor, and you can make a judgement about how likely it is you’ll be able to find the word.  

Rodin’s statue  The Thinker  (public domain)

Rodin’s statue The Thinker (public domain)


Dante, thinking about why he’s naked. Now you’re thinking about Dante thinking about why he’s naked: metacognition!


Though it doesn’t make much difference to us in our everyday lives, the distinction between these two types of theories is important to researchers because the direct-access theory focuses on the act of temporarily forgetting a word, while the metacognitive theory focuses on the experience of temporarily forgetting a word. The metacognitive theory allows us to be a bit more precise in our definitions – for example, the metacognitive theory makes a distinction between “I don’t know the word but I will in a moment” and “I don’t know the word but I’d recognise it if I saw it”, which could be very different processes in terms of what the mind and brain are doing [v].

Now, I know my parents read this (Hi Mum! Hi Dad!) and I bet that Mum is currently thinking, “Words have got stuck on the tip of my tongue much more often as I’ve got older; I wonder if that happens to everyone?” Yes, Imaginary Mum, that is indeed the case! It's also the case that people who are bilingual have more tip-of-the-tongue experiences than other people [vi], but none of my family are fluent in more than one language so Imaginary Mum is less likely to ask that question.

It might be the case tip-of-the-tongue words become more common as we age because the links between phonological and semantic knowledge about words become weaker, but also because the older you get the longer the gaps that are possible between the time you get asked to recall a word and the last time you used it, which can also weaken the association between phonological and semantic knowledge regardless of how old you are [vii]. The good news is that as you age you are also less likely to experience “persistent alternates” – the wrong word, but one that keeps getting in the way when you try to find the right word.

But Clare, how do I stop getting words stuck on the tip of my tongue? You can't, alas. You can make them less likely, but I don't know that the advice I have on that front (other than “find the Elixir of Youth, I guess?”) will be very popular, because it involves lowering your caffeine intake.

Hands holding a takeaway coffee cup

Hands holding a takeaway coffee cup


No, not my coffee!


Yes, indeed, your coffee. Just ask Lesk and Womble [viii]. They fed caffeine pills or placebo pills to their participants, and showed them word lists followed by unrelated general knowledge questions. The people who’d taken the caffeine got more general knowledge answers stuck on the tips of their tongues than people who’d taken the placebo.

Are you still clutching your tea and sobbing gently, like I was when I read about this study? I have some good news. When Lesk and Womble did the same task but the word lists were related to the general knowledge questions, caffeine caused fewer tip-of-the-tongue words than the placebo. So if you really want to carry on mainlining Red Bull, remember Lesk and Womble and turn it to your advantage by finding a predictable environment to work and live in.


Got a question that only psychology can answer? Talk to me!


…Still stuck on those questions from the start? Here are the answers you are searching for: Caracas, furrow, Julie Walters.