Every week I will demonstrate an example of poor English where a different word is used from the one intended. Sometimes this creates a grammatically incorrect sentence. Unfortunately, the mistake is usually so pervasive that we all do it and such errors are usually made by those who should know better – journalists working for national or global media outlets such as newspapers and television
Can / May
Can I ask you a question? I bet you didn’t know you were using the wrong word here did you?
May I ask you a question? Do you know the difference?
Both in a way are grammatically correct but the first sentence does not mean what you think it means.
Can I ask… – What you are asking here is Am I able? Well yes… if you are able to speak then you are able to ask me a question
May I ask… – What you are asking here is Do I have your permission to ask you a question?
As language evolves though, meanings change. The OED states that it is no longer grammatically wrong to use “can” when you mean “may” but language perfectionists would rather keep the distinction. For further details on the exceptions, visit Grammar Monster