Visible crew/equipment: When Professor Higgins is having Eliza practice saying the letter H by blowing into a tube to make the flame waver, the paper she's holding is actually Rex Harrison's lines. Once the paper starts to burn and the camera angle changes, you can read them and it's practically all of his lines for the whole scene.
Visible crew/equipment: After Eliza has left Henry Higgins, he goes back home, turns on the record of Eliza's voice and sits down to listen. Behind him on the floor to the right, there is a shadow with quite a bit of movement, as if someone was nearby. There is no one else in the room; and it can't be Eliza's, because she is still outside the room, and hasn't approached the doorway yet.
Continuity mistake: In the song "I'm Getting Married in the Morning" there is a bottle of gin or something similar on the bar. When the bar-lady pours Alfred a drink, the bottle is close to the bar handles (those knob things in local pubs, they control the amount of beer pouring out), but as the song progresses the bottle gets further and further away from the bar-lady. DVD Showing.
Continuity mistake: The movie starts and people rush under a heavy rain. A group walks by the fruit stalls, and a sellers bumps into them and walks towards the camera. A frame later there's a quick cut and, though the angle remains the same, the people have vanished and been replaced by different actors, plus the seller has turned around and is walking away from the camera. Really odd.
Continuity mistake: In the scene where Eliza starts to sing the song "Loverly". She goes "all i want is a room somewhere." and at ". oh wouldn't it be Loverly" she sits down and her apron is halfway between her legs. When she continues the song the angle changes and her apron is now covering both her legs, at her right a man disappears and at her left a woman, at her left a man walks later than in previous angle the sacks behind her change formation and the carriage wheel is now lighted.
Other mistake: When Eliza throws the slippers at Higgins, one bounces off him and falls in the area of the doorway and the other lands in the middle of the hall. One slipper is seen in the hall in two different scenes, then when Higgins goes to pick them up they are both together in the hall.