This is what my friend Kasia was told who is now in Poland. She lives in Canada but she's Polish and can't roll her r's, she was told she should see a speech therapist haha. I don't doubt that this is true because my friend is a linguistics major.
The most common lisp is probably the s-lisp (or lithp). Having both the s-lisp and the r-lisp should mark a Polish person out to be a good candidate for speaking English quite well.
I can pronounce my Polish r properly (usually), and I can roll my tongue and turn it on it's side. Sometimes I can hold my tongue so I don't have to bite my lip or eat my words.
Tell her to wear high heels. It helps most girls roll their R's.
Seriously, I had a funny experience in a primary school where I was directing a play in English. I chose on girl to say a rhyme because she was wonderful at saying 'th'.
Over hill and over dale, Through the forest and the fire, beneath the moon so white and pale, through the mud and through the mire.
A couple of weeks later I asked her to recite it again, (English letters for pronunciation)
"Owa hiw an dower dayw, thwu the fowestan da faja, beneefda moon so wayt an payl, thwu the mud an thwu the miyr"
I couldn't believe it. I turned to my Polish assistant and asked, "What's her Polish like?"
"The same" came the reply.
I hadn't known 'th' is considered a lisp.
I have one Polish student who claims not to be able to say 'cz' and 'sz' properly. I asked her how on earth she could speak Polish without being able to do it... "Like Kasia Cichopek!"
