A player that is lvl 4 and uses bonus action to swing his 2nd weapon. He then wants to use Action Surge. Is this possible? Yes – action surge does not use a bonus action

— Mike Mearls (@mikemearls) August 26, 2017

Thank you so much. Would he get a 3rd & 4th swing or just a 3rd swing?Just 3rd – no bonus action included in extra action. With surge, would be 2 actions + 1 bonus action total

— Mike Mearls (@mikemearls) August 26, 2017