to understand or with/in/at

[E2e4]

I have a problem to understand this simple sentence. or

I have a problem with/at/in understanding this simple sentence.

Thanks

[Eugene2114]

I have problem understanding how the gatedriver below works

Hi E2e4,
I found a couple of sentences on the pattern:
I have problem with understanding English speech
I have a problem understanding the Show frame-relay pvc command contents.
I have a problem understanding/using "vertical-align
I have a problem of understanding the definition of cumulative distribution function for a continuous variable.
Problem with understanding arraystoreexception
- I would vote for "I have problem with understanding..."
Regards.

[Beeesneees]

I have a problem...
or
I have problems...
Eugene!

Other than that, you're correct, but you could also just as naturally use:
I have a problem understanding this...
I have a problem in understanding this...
_________________
Cheers m' dears!

[Dozy]

I have a problem understanding this simple sentence. -- This is OK; you don't actually need any preposition.

I have a problem to understand this simple sentence. -- You may hear this form used, but to me it does not sound quite right.

I have a problem with understanding this simple sentence. -- Acceptable.

I have a problem in understanding this simple sentence. -- Acceptable.

I have a problem at understanding this simple sentence. -- Wrong.

[Eugene2114]

Hi,
Sorry Beees, to have been sloppy: "a problem" but "problems", of course. I chose 'the safest', to my mind, option - "with understanding" -
though myself would use "have a problem understanding" with pleasure.
Thank you.