Which of the following are grammatical?

  1. I cannot help but think.
  2. I cannot but think.
  3. I cannot help thinking.

I was taught (1) is not correct. Is it true? Or are they all correct? Is there any other way(s) to express what the speaker is trying to say using the words "help" and "think" apart from the three ways I mentioned?

  • 7
    They all seem correct to me. 2 is maybe more poetic or archaic.
    – GEdgar
    May 28, 2012 at 13:49
  • 2
    It seems that "cannot help but" was ungrammatical two centuries ago, but it's been in use for the last 100 years, and now appears to be reasonably widely used. See this Google Ngram. So (2) is indeed older, as @GEdgar says. May 28, 2012 at 14:31
  • 2
    Related: “I can't help it.” Why help?
    – RegDwigнt
    May 28, 2012 at 15:37

1 Answer 1


I would imagine that whoever told you that (1) is not correct did so based on a prescriptive rule against double negatives. The advice is mirrored here on a list of common grammatical errors in English, and here in an English for Dummies book excerpt. The problem, however, is that it is kind of silly to take something that people say all the time and declare that it's ungrammatical. I don't know of anyone who would hear the sentence "I can't help but think that he's a criminal," and then wonder whether I think he's a criminal just because of the double negative between cannot and but.

As far as I know, (2) is correct, but nowadays it is not usually said or written, except when trying to achieve an overly formal or old-fashioned tone.

For (3), the sentence is correct and is largely interchangeable with (1). This page claims that (1) is primarily used to mean:

I am forced to the conclusion that S[, though I'd rather not believe it].


I am forced to the experience of S[, though I'd rather not have it].

(where S is some sentence, and the sense conveyed by the braces is optional), while (3) can either take that meaning, or:

I'm always thinking about [the fact that] S[, though I'd rather not do that].

I can see the point, but they both sound fine in either usage to me. Maybe that's just my experience.

One final remark is that all three of the constructions would have a certain formalism to them if spoken; I imagine it is much more common to use the contraction can't in place of cannot in that case.

  • Another equivalent construction which possibly better captures the semantics of (1) is "I cannot help [save for/except] to think..."
    – AMDG
    Jun 13, 2022 at 0:28

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