Take these examples:
The first ex. is, possibly, an elliptical c. from 'can't help but', common in spoken E, but I doubt it is widely accepted as correct language.
- I can't but think.
- I can't help but think.
- I can't help thinking.
In ex. 2 and 3, my question is: what's the but doing for you with an infinitive in (2) that a simple conjunctionless gerund doesn't do in (3), anyway? Some figured out that the more words you use, the heavier the so-called thought you're expressing. Also, I can feel a slight nuance difference between 2 and 3 - I can't pinpoint what it is, though.
Ex. 3 is usually considered to be more correct than the wordier 2, language-wise.
I couldn't help falling in love. ( no 'but'). - suggests helplessness??
However, it is very common to hear:
I can't help but yell at him.
I couldn't help but cry.
I can't help but proceed with the interview.
I have a feeling that the last exs are more charged, emphasized. - (meaning: I had no choice but to yell / cry /...)
Student or Learner