I am interested to know if, for some, there is a subtle difference between the two phrases in the title. I am equally interested in knowing if there is a subtle difference.

4 Answers 4


There is definitely a difference to me. They do not mean the same thing.

Being interested in something describes a general interest that you hold—something that you tend to find interesting and devote some part of your time doing or at least thinking about.

Being interested to do something, on the other hand, implies that right at this moment, you find the thing in question interesting and would like to [do whatever it is]; but it does not speak to your general interests.

With the verb know, the latter tends to be a more accurate description of what’s going on: knowing is not something that we often need to talk about as one of our interests in life. For me personally, I frequently use it in the conditional:

I’d be interested to know how much of our recycled waste is actually recycled.

In other words, it just struck me now that that particular piece of information would be an interesting one to have; I don’t count knowing how much of our waste is recycled among my general interests, though.

If I do count something as a general interest, I would use the gerund form:

I’m interested in knowing everything I can find out about the mating rituals of grasshoppers.

This implies two things:

  1. That one of my general interests is the mating rituals of grasshoppers, and I therefore spend lots of time in learning everything I can about them (similar to “I’m interested in art”, except with an action as the interest instead of just a broad concept).

  2. I have very little to no social life.

This is not really a hard-and-fast distinction, but it’s a good rule of thumb. There are many cases where a gerund construction can, from context, be shoehorned into the sense of ‘current, fleeting interest’ rather than ‘permanent, general interest’:

Would you be interested in going out for dinner tonight?
Would you be interested in cooking for me tonight?

This is partly to do with the conditional, which tends to reinforce the ‘currently’ sense of interested; if you describe general interests, you would usually just use a straightforward present:

Are you interested in going out to restaurants?
Are you interested in cooking?

These last two are definitely ungrammatical to me with the infinitive construction:

*Are you interested to go out to restaurants?
*Are you interested to cook?

  • agree with your comments, especially the last one. I came looking for confirmation of my instinct that the pitch phrasing *"Interested to know more about X?" is ungrammatical. I would only use the "to know" form with a conditional, as mentioned: At the moment, I would be interested to know whether this is a difference between AmE and BrE / [further dialects]. Sep 30, 2014 at 7:30
  • I don't consider 'be interested in knowing' to be a typical member of the 'interested in ing-form' expression. 'I'm interested in knowing why you went there' is a hedged paraphrase of 'I want to know why you went there' rather than a declaration of one's personal interests (I'm interested in reading / writing / cinema / knowing all there is to know about Eskimo words for snow). (The last example shows a rare exception.) Mar 12, 2018 at 23:41
  • @Edwin That’s interesting (!) to me, because it certainly is a typical member of the general expression to me. “I’m interested in knowing why you went there” is very odd to me; I would never produce it myself, though I probably wouldn’t really notice it much if I heard it in regular conversation. I would only ever say, “I’d be interested to know why you went there” or “I’d like to know why you went there”. Mar 13, 2018 at 9:01
  • 10 000 Google hits for "I'm interested in knowing why you" (but I haven't time to de-false-positive). Mar 13, 2018 at 9:19

There is, at least in American English, no discernible difference as far as meaning between the two phrases. Both phrases introduce something which you wish to learn. However, the form interested in knowing is a bit more common that interested to know, which does sound a bit more awkward (at least in my opinion).

Another phrase, if you're curious, would be interested in learning.

I am interested in learning whether or not dogs have legs.

  • 6
    They do. Usually 4.
    – Sam Holder
    Feb 17, 2011 at 22:23

A common view generally is that the -ing form focusses more on the "middle" of an action when a choice between it and the infinitive is available. I think this view could work here, though the difference is subtle as you say.


Based on my intuition and the time I've spent trying to understand Jean Yate's The Ins and Outs of Prepositions I would suggest that 'in' gives a more detailed interest in learning, perhaps a specific detail or for a specific goal' whereas 'interested to know' is perhaps a general interest, but maybe nothing more.

  • It’s rather the opposite to me. Sep 16, 2014 at 8:29
  • Interesting can you explain why or give some detail to your difference of opinion? My basis is on the fact that 'in' draws on the idea of an enclosure of space. The infinitive, contrarily, only describes the notion of interest. Sep 16, 2014 at 8:55
  • You can’t always (if even usually) derive that much meaning from generic, abstract meanings of prepositions. They appear in many idiomatic constructions where their meaning is either subtly or entirely different from their basic meaning. See my answer for how the constructions here differ to me. Sep 16, 2014 at 11:48
  • I read your answer yesterday. I have to respectfully disagree that prepositions only convey generic, abstract meanings. If you haven't I highly recommend taking a look at The Ins and Outs of Prepositions. In regards to our discussion though, I would ask you which of the following two sentences convey a stronger sense of interest: 'He is interested in her,' or 'She interests him.' Sep 17, 2014 at 1:33
  • 1
    Perhaps this can be chalked up to an issue of regional usage. For midwesterners I believe the use of 'in' in this case implies a much stronger attraction than 'She interests him' would. I think it boils down to a let's agree to disagree, but it would be interesting if some other people could chime in to give their opinions. Sep 18, 2014 at 2:28

Not the answer you're looking for? Browse other questions tagged or ask your own question.