@paok1970,
paok1970 wrote:
Is it "to be stuck FOR words" or "to be stuck ON words"?
If both are possible, do they mean the same thing?
If not, when should I use each of them?
Would you please give me a couple of examples?
Thank you.
No, they don't mean the same thing, and I don't think either phrasing is common. That said:
You might say you're "stuck for words," when you're not sure what to say and/or how to say it. More common would be "at a loss for words."
You might say you're "stuck on words" if you have a limited vocabulary and are therefore having trouble reading something (or only reading slowly because you keep consulting a dictionary). In this sense you're "stuck" because you can't proceed (at least not rapidly).
They are other possible contexts, too.
In this context "stuck" basically means you're unable to move/proceed because something is keeping you in place.