A4. Permission: We use 'can' to ask for permission to do something (e.g. Can I ask a question, please? Can we go home now.), and to give permission. (e.g. You can go home now if you like. You can borrow my pen if you like.)
a. 'could' is more formal and polite than can. (e.g. Could I ask a question please? Could we go home now?)
b. 'may' is another more formal and polite way of asking for permission and giving permission (e.g. May I ask a question please? May we go home now? Students may travel free.)
Idiom 365
Good Samaritan: someone who helps people when they are in trouble or need without compensation
Example: A traveller who was robbed, beaten, stripped and left half dead alongside the road. A Good Samaritan comes by and helps him.