Often you hear people go "um" and "ah" (or alternatively "erm") while they are thinking what to say.

I have come across "um and ah" or "umming and ahing" but this sounds rather informal and colloquial.

I was hoping there is a more formal, single-word verb that describes this action.


13 Answers 13


I think the right word depends on what is going on for the speaker:

If they are naturally just not a fluent speaker, you'd probably say they are stammering, stuttering or faltering.

If they are nervous, you might say they are hesitating (or, again, faltering).

If they are being evasive, struggling to find words to avoid saying the wrong thing, you might say they are hemming and hawing, umming and ahhing or hesitating.

It's hard to neutrally describe a pattern of speech without imputing some kind of thought process.

  • If they're nervous it's stammering (but that's also known as stuttering. Only if they didn't actually have a stutter would I point out the fact that someone was stammering).
    – Mazura
    May 7, 2020 at 4:52
  • 2
    In the evasive area, it's Humming and hawing in UK, and apparently umming and ahhing in AU
    – mcalex
    May 7, 2020 at 5:27
  • 1
    I think hemming and hawing is indeed the proper idiom 'for when a person goes “um” and “ah”'. May 7, 2020 at 6:15
  • Thanks, have incorporated these comments. May 7, 2020 at 6:19
  • 1
    +1 but I think you forgot the case of "thinking" - "uhhhhh" & "ummmm" are incredibly common in English (US at least), but don't always fall into your three categories. Sometimes it's simply a way to organize thoughts before speaking, no nervousness or evasiveness required. I'd still call it faltering, or the point of my comment, what would you/others on SE call it in that case?
    – TCooper
    May 8, 2020 at 23:27

My first thought is falter, applying the sense of "behave uncertainly" to speech:

"They ran in here and then... um..." The witness faltered in her testimony.

Merriam-Webster indicates the transitive form for this ("faltered her testimony"), but one could generally say that speech filled with these utterances is faltering or that the speaker is faltering. Note that this doesn't assume the speaker's intent -- thinking, procrastinating, waiting for a distraction to end the interaction, etc.

However, on second thought the right word may depend on the purpose or effect of the utterances. They fall into the category of speech disfluencies, which serve a large number of purposes (differing between languages and cultures which particular sounds are supposed to mean what): filling silence, indicating that the speaker is thinking, indicating that attention is being paid, and so on. In North America it would be perfectly reasonable for someone to say "ah" with purpose and confidence to express acknowledgement, or "um" to break into a conversation. While faltering describes the instances in which these utterances are used to indicate the speaker is thinking, it probably does not apply to every instance of the example sounds you gave.

  • 2
    Note that falter is intransitive: A witness would falter in her testimony. May 6, 2020 at 22:01
  • I agree that faltered in her testimony sounds considerably more natural, but I wasn't actually able to find a source that excluded the transitive. May 7, 2020 at 3:31

Those specific types of words are called speech disfluencies, but that is not a verb used to describe what one is doing when they use those words.

This is a bit of a nebulous question since speech disfluencies are used in so many common situations that among some populations they can represent up to 20% of the total words used in everyday conversation.

Verbs used to describe what you are doing when using a disfluency could include :

  • If you do not know what to say, and you are indicating to your audience that you are taking a moment to think about it, you may be pondering, considering, or contemplating.
  • If you do not know what to say, and the silence is making you uncomfortable, you are fillering.
  • If you do not know what to say, and you you are trying to buy time, you are delaying.
  • If you know about what you are trying to say, but you have a neurogenic speech impediment that makes saying it difficult, you are stuttering or stammering. (Some cases of filtering may also be described this way)
  • Stutters are often caused by duress; so, if it is caused by a stressful situation you may be faltering or cowering
  • If you know what you want to say, but are unsure if you should say it, you are hesitating
  • If you know what you want to say, but purposefully include the disfluency for dramatic effect, you may be emphasizing.
  • If you are parroting another person's disfluencies you may be mirroring or mocking
  • Tranquilled has already written 'speech disfluencies' in their answer. May 6, 2020 at 23:02
  • @DecapitatedSoul Sorry, my original answer was a bit brief so my intent may have been lost. I was not trying to say that speech disfluency was the answer, but to bring attention to it as the topic of discussion. Tranquilled's original answer made it sound like he was saying that speech disfluency was the answer, but I was trying to point out that the OP was asking for the verb of what you are doing when you use one.
    – Nosajimiki
    May 7, 2020 at 15:06

Johns Hopkins Medicine's site says that saying words like "uh" often is called "cluttering".

If you do this, you "clutter" when you speak.


  • Thanks, @Hachi. I didn't realize that there was a hyperlink tool in the answer toolbar. That makes the answer much easier to read. May 6, 2020 at 11:37
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    Good find, but I'm wondering if this is a specifying definition. The sense is absent from most of the dictionaries I've checked, while Collins gives a broader definition, much overlapping with that of 'garble': to speak so rapidly and inexactly that distortions of sound and phrasing result. Is there the definition you use given by an authority outside a single specific organisation? May 6, 2020 at 11:53
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    This is not the general answer to the question, it's only for the rare case of fluency disorder. Most of the time people go umm and ahh, it has to do with embarrassment or not knowing how to explain, not any disorder.
    – smci
    May 7, 2020 at 3:53
  • The link also states "If you clutter, you often speak fast and merge some words together or cut off parts of them." Which is completely different from the behaviour described in the question. So I dont think this is a good answer.
    – Cyberwiz
    May 7, 2020 at 8:03
  • I was thinking that there is probably a medical term for this, though come to think of it, I wonder if, more specifically, psychologists don't perhaps have a generic term for the action of saying 'um' when thinking what to say, because it not only applies to people with a disorder. Everyone does it at some point. May 9, 2020 at 14:10

Scottish English has the perfect word for this:

haver: To hem and haw

You can hear it in this famous Proclaimers song.

Unfortunately you will get funny looks if you use it, unless you speak with a Scottish accent. See here for an example.

  • Haha! I vote for adoption to common English :). May 8, 2020 at 22:38
  • This is exactly the word that came to mind.
    – mdoar
    May 12, 2020 at 19:42

These words are fillers, pure and simple- the speech equivalent of wheat and fiber inserted into hotdogs because they are cheap materials. These words are similarly cheap as they require zero mental expenditure, but are aimed to give the appearance that the speaker has, like, you know, umm, totally something to say. @Nosajimiki has suggested fillering, which would seem the natural transformation of the noun to verb, but the word doesn't feel natural. I suggest padding which is a common verb connoting the addition of fillers, even in a linguistic context:

From Merriam-Webster unabridged: pad

a (1) : to expand or lengthen (as a book, magazine article, speech) by the insertion of additional material that is usually essentially superfluous and often extraneous to the point of being irrelevant and that is usually used merely to artificially bring the thing so expanded up to some desired size or length or that is used for some other usually equivocal purpose (as to add impressiveness, suggest intellectual depth, mask an otherwise distasteful theme) : inflate — often used with out

An example sentence by me: "The other answers are thoroughly padded with worthless fillers."

Granted, padding in writing or speech is not restricted to cheap fillers, as it is one of the oldest tricks employed by students doing homework at the 11th hour, discovering 17 ways to say the same thing in as many sentences. But it fits the bill.

  • I don't think the average person who says "um" while searching for the right word or phrase to say has the kind of active intent you are attributing to them.
    – arp
    May 9, 2020 at 13:57

The formal linguistic term for this sort of non-content filler is hesitation noises. (Wikipedia has a cool list of hesitation noises in different languages/generations.) So, for a verb, you might just use hesitate.

(I was going to also reference hemming and hawing, but that's hesitation or waffling words, not semantics-free filler noises.)


I would say that the person is possibly "prevaricating". However, it's important to note that this implies some evasiveness behind the "um"s and "er"s.

For a non-evasive verb, I would probably go with "umming and ahhing", as it's clearly understandable. There are technical terms for it - but they don't really describe it very well!

  • 6
    "Prevaricate" implies a behavior (lying, evasiveness, skirting the truth) that is intentional or at least conscious, while people who use "uh" and "um" a lot often are simply uncertain about what they want to say or have a fluency disorder. merriam-webster.com/dictionary/prevaricate May 7, 2020 at 0:19
  • 1
    Another similar "almost" word is vacilate as in "to hesitate in voice of options or courses" where the options are the words they're about to say.
    – Criggie
    May 7, 2020 at 7:24
  • @IsabelArcher A point I think I made clear in the answer? May 7, 2020 at 7:24

I'm not sure if there's a specfic verb as such.

You could perhaps use 'ponder'.

If you asked someone a question and they answered with an 'um', you might say one was pondering for a moment.


Anomia, a symptom of aphasia:

Anomic aphasia (also known as dysnomia, nominal aphasia, and amnesic aphasia) is a mild, fluent type of aphasia where individuals have word retrieval failures and cannot express the words they want to say (particularly nouns and verbs). Anomia is a deficit of expressive language. [...] Individuals with aphasia who display anomia can often describe an object in detail and maybe even use hand gestures to demonstrate how the object is used, but cannot find the appropriate word to name the object.

Further reading on expressive aphasia loops back to "disfluency", as mentioned in Tranquilled's answer.

  • 1
    Searching for the right way to say something while speaking isn't the same thing as aphasia. I will often use "um" or "uh" during the normal flow of a conversation when considering the words I want to use, but I also have epilepsy induced aphasia during partial seizures and I can speak from personal experience that the two have nothing in common
    – Kevin
    May 8, 2020 at 16:42
  • @KevinWells - As far as I know I don't have aphasia but I do sometimes suffer from the ums and ahs. I think the other answers made me forget the wording of the original question and think of someone whose speech was diminished greatly by the ums and ahs. One thing I learned in the further Wikipedia reading mentioned in my answer is that the medical community classifies different types of aphasias. At the time of my edit, disfluency was listed as a symptom of "expressive aphasia". Willing to retract answer if it's objectionable to you though.
    – bf2020
    May 8, 2020 at 17:03
  • Not objectionable, and it seems that you're right on this that it can be part of expressive aphasia. That seems like a strange classification to me since it isn't really an inability to speak and is almost universal among speakers of every language, but everything is on a spectrum
    – Kevin
    May 8, 2020 at 18:15
  • And I certainly didn't mean to come across as offended or anything, just wanted to speak to the differences from personal experience. The normal um's and uh's of conversations for me are just giving me a bit of extra time to think through exactly how I want to say something, whereas when I have an episode of aphasia it is like my brain literally can't put words to the thoughts I'm having. Sometimes I can get out a word or two, but sometimes I use entirely the wrong words or no words at all. That said I know different people have different experiences of aphasia so I retract my criticism
    – Kevin
    May 8, 2020 at 18:19

The most common term I've heard for these is verbal pauses.

Also known as verbal fillers or filler words.


I think it definitely depends on the context. If it is a country's leader giving an address, and they are are using some ums here and there, I might say they are thinking, or calculating, possibly processing, making sure they choose the right words to convey the message. Similar to the hourglass, or spinning icon that we get on our computers when clicking on some links, indicating that some processing is being done in the background. This comes to mind, because when Obama was in office he used allot of ums in his speeches.

Another context could be a student giving a speech in front of her classmates. It is likely that the student is not accustomed to addressing a group of people, and is nervous. In this case the ums, likes, and uhs could be described as fumbling, faltering, perhaps even distressing. I'm speaking from experience on this context. I have to battle with myself omit the so called filler words anytime that I have to address a group of people who are more or less strangers.


I had always believed until now the right term was prevaricate ('to speak or act in an evasive way').

But the (multiword) phrase "ummed and ahhed" is accepted.

I don't think the answers referencing dysfluencies and speech pathologies are relevant since that's not the typical reason. It's usually because the speaker is embarrassed, flustered or caught doing something they can't explain.

  • 4
    This is not necessary prevarication. In fact, it almost certainly is not. The vast majority of people speak with filler words (vocalized pauses) punctuating their words when they are speaking normally and being completely honest. We do not hear it in others' speech patterns unless we're specifically looking out for it, and that often requires specialized training. (Speech pathologies can and do exaggerate this, of course, but it's a near-universal phenomenon, except for carefully trained public speakers who have worked very hard to avoid it. And even they're not immune.) May 7, 2020 at 4:02
  • @CodyGray: it depends on the context; and specifically whether the speaker is embarrassed, flustered, caught misrepresenting, or just tongue-tied. In adults, doing this excessively could suggest lack of truthfulness; or being bad at speaking in public. More commonly than speech pathologies.
    – smci
    Dec 16, 2022 at 5:01

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