Asking for/giving permision

Giving Permission:

• Yes, please do.
• Sure, go ahead.
• Sure.
• No problem.
• Please feel free.
• Go right ahead.
• Please feel free + infinitive

Refusing to give permission:

• No, please don’t.
• I’m sorry, but that’s not possible.
• I'm afraid that's not possible.
• I'm afraid, but you can't.
• I'm afraid I'd prefer if you didn't / don't.
• Sorry, but I'd rather you not do that.
• Unfortunately, I need to say no.