Strictly speaking, can is an auxiliary verb that is used to express mental and physical capability. May is an auxiliary verb that is used to express permission. However, the sharp dividing line between the use of can and may has eroded, due to the English language’s seeming evolution toward informality.
Today, can is used to express mental and physical capability and in informal circumstances, it expresses permission. A child might ask a teacher, “May I have an apple?” as the child is asking a superior if he will be allowed to receive an apple. A child might ask another child, “Can I have an apple?” as he is speaking to a peer.
May is more polite than can, it is used in situations of courtesy, formality and making requests of superiors in age or rank.
“I am bringing this action to ensure that legally supported expenditures can continue to be made and to address the question of how the state payroll is legally managed during the budget impasse,” Madigan said in a statement. (Huffington Post)
Ekin company says the vehicle-mounted system is a state-of-the-art and unique product, which can scan all the number plates of vehicles within its effective range through 180-degrees and match the speeds of the vehicles to their number plates. (Daily Mail)
Can I leave my child home alone? (Marshfield News-Herald)
Can I Throw This Student Loan Back to My Ex-Wife? (Huffington Post)
May I get back to you within two hours to determine next steps?” (U.S. News & World Report)
May I Lie to My Husband to Get Him to See a Doctor? (The New York Times)
May I also remind you that Sharma’s predecessor Dr DK Sakale was also found dead in similar suspicious circumstances, when his body was found burnt to death,” Surjewala told reporters. (First Post)