Can I = is it humanly possible May I = would you give me your permission
Current wisdom suggests the two words can/may be used interchangeably, but "may" is considered a little more polite making it more appropriate for formal situations.
I agree with those that say that both can & may should be accepted. English allows both precisely because English has almost completely lost the distinction between indicative and subjunctive. One way to display distinction between can and may in Spanish grammatically is the distinction between the indicative and subjunctive. But is there a difference in this sentence between Spanish subjunctive and indicative? I don't think pueda works here, so I don't think Spanish would use subjunctive here, but we will need a native speaker to chime in to confirm. "Pueda llevar su bolsa?" If one wants to be polite and deferential here, then su is used. "Peudo llevar su bolsa." The pronoun tu indicates familiarity and deference, not subjunctive in this case. In colloquial English, "Can I carry your bag"--said to someone you know--is the norm in the midwest U.S., whereas "May I carry your bag" is more formal and would be said to someone you don't know--the granny who is having a hard time--and so su would be needed in Spanish equivalent. IMO, the use of pronoun tu here indicates "can" is best but I wouldn't fall on my sword over it.
Is there a difference between "May I" (do I have permission) and "Can I" (am I able) in Spanish?
I don't think so, i.e. puedo can mean both, although it would make little sense to ask someone else of what you are able to do IMHO.. anyways, it will always be clear from the context
What is wrong with " can I take away your bag?" I was at a Latino restaurant just last night, and that's what I was asked.
For "take away," I would have expected to see the pronominal form of "llevarse." That would be, "¿me puedo llevar tu bolsa? "
"Can" is not correct. "May" is correct here, yet not accepted. Reported 3/1/18
"Can I" is good here. It's what people usually/often say. It may not be perfect English but if the point is to learn Spanish then it's important primarily to understand the sentiment being conveyed by the spanish sentence, no?
What I mean is if someone comes up to you and says "puedo llevar tu bolsa" it's more important to know what they're asking than to get bogged down worrying about whether they are saying 'can I' or 'may I'.
That's the way I think about it anyway; it helps me worry less about Duolingo's sometimes questionable English grammar.
There's absolutely nothing wrong with using "may," which is what I was taught should be used to ask permission. However, that usage is neither universal nor intrinsic to the definition of either "can" or "may" (cf. Oxford online dictionary.)
Regardless of one's personal opinion regarding proper English usage, Spanish makes no such distinction and that should be enough for Duo to accept either "can" or "may."