Seeing this EL&U question: 'saying thanks to someone answering your email ASAP who is important for you', the first word that came to my mind was promptitude which, as the definition states, can convey both punctuality and non-delay-ness(immediate-ness)

So I thought this would be a good answer for said question

thank you for your promptitude

But after googling the subject (to see if this is an american expression as required by the OP), I stumbled upon the word promptness which seems to convey the same meanings of punctuality and non-delay-ness(and to be a lot more popular than my first frenchy choice). So, I thought that one could equally/better propose

thank you for your promptness

Now, I have no problem recognizing promptness as an equally/more valid word for the same usage. But, at the same time, my problem lies precisely there: it is too much an equally valid word for the same usage, because when I went hunting for small nuances between the two words(because someone on EL&U/ELL once said that synonyms usually denote of different connotations) I couldn't find any.. I am further appalled by the fact that they stem from the same root.

Yes, the question:

Am I wrong in :

  1. assuming that promptitude & promptness have no distinct connotations (in this context particularly)?
  2. thinking that perfect synonyms are something of a rarity?
  3. thinking that same-root perfect synonyms are something of a rarity?
  4. a combination of 1., 2., 3. and some other speculation of mine?

Why? (added for the charmingly joking nature of EL&Uers)


After receiving some comments and one answer I have to add:

Again, I have no problem recognizing promptness as an equally/more valid word for the same usage.

But it seems to me that we have these two words from the same root that mean the same thing. How come? Is it just because one is becoming obsolete and that's how words die - another one comes and slowly but steadily takes its place? or is it something different?

  • If it helps, Merriam-Webster gives one sense of "promptitude" as the habit of being prompt; a sense it denies to "promptness". Futhermore, the OED has two senses for "promptitude", and only one for "promptness". So, aside from the definition which makes them synonyms, "promptitude" also means "A prompting, an impulse; an inclination." (which is marked with Obs., unfortunately).
    – Dan Bron
    Sep 18, 2014 at 17:43
  • @Dan: The noun "promptness" itself could be used in the sense of something habitual. Depends on the context. If your child's teacher wants to talk to you about the kid's tardiness, you would likely suppose there to be a pattern of that behavior in evidence.
    – Robusto
    Sep 18, 2014 at 17:47
  • @Mina Huh, I thought I checked that and didn't see the same meaning. Oh well. That said, OneLook does provide two meanings for -ness and only one for -itude (which is actually the opposite of what I found in the OED).
    – Dan Bron
    Sep 18, 2014 at 17:48
  • @DanBron Confusing, isn't it?
    – Mina
    Sep 18, 2014 at 18:00
  • 1
    @Daniel: My starting point is that I already know promptitude is the rarer and more dated term, so it's just a matter of finding appropriate ways to back that up. If you compare the dates on the (est. 49) results for qualities such as promptness with just 8 for ...promptitude, you get the same story. Sep 21, 2014 at 0:47

2 Answers 2


I have to say that, in British English, I cannot recall ever having seen 'promptitude' used in any context.

In the example situation quoted it would be normal to say 'thank you for your promptness in replying' or, more likely, 'thank you for your prompt reply.'

  • 2
    Yeah, and if I got an email using the word "promptitude", I would think the writer was either a pompous ass or someone not familiar with English. It's an email! Sep 18, 2014 at 20:55
  • I really have to remember this next time I write an email.
    – Mina
    Sep 18, 2014 at 21:02
  • But it seems this guy and Marc from Long Beach here didn't get the memo.
    – Mina
    Sep 18, 2014 at 21:08
  • @Tony Balmforth You seem to say that the answer to 1. is 'Yes, there is a huge difference: One is idiomatic, the other is not at all because, as a native speaker, I have never heard of it' It is a perfectly valid argument for me +1
    – Mina
    Sep 19, 2014 at 4:56
  • But this doesn't fully answer my question: How come we have now two words from the same root in English that convey the exact same meaning?
    – Mina
    Sep 19, 2014 at 5:00

Google Ngrams

The examples of "prompitude" are almost exclusively from historical quotes

A picture is worth a 1,000 words:

enter image description here

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