How a wing generates lift

Give an explanation of why an aeroplane is able to fly.

The wing deflects air downward, so the air pushes the wing upward. The wing's shape and angle of attack turn the oncoming airflow down; by Newton's third law that change in momentum produces an upward force, and equivalently the air flows faster over the top surface, creating lower pressure above than below (Bernoulli). Lift scales as $\tfrac12\rho v^2SC_L$, so speed and wing area matter; engines provide thrust to overcome drag. Avoid the myth that air over the top must rejoin the bottom flow at the same time.