To my ear, there's no difference in choice or meaning. Your teacher's preference wins the Google race by seven to five: "not at all surprised" 7,260,000 hits "not surprised at all" 5,320,000 hits
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.
Anonymousare they both possible? if yes, then what's the difference between them?Yes. There's no difference in meaning.