The One with the Dozen Lasagnas - S1-E12
Other mistake: At the end, Monica is playing as red, but we see the blue team score on the foosball table. However, Monica states that she scored and beat Joey and Chandler again. A previous correction says to look closely as the red team scores, That correction is completely invalid as the player in goal is red. Why would Monica score in her own goal? And Also the blue players can be seen to spin. (00:22:10)
Revealing mistake: When Joey is filming his scene for the movie, look behind the director to see a box saying 'Monica' indicating that it was shot on the Friends set rather than Al Pacino's set. (00:16:30)
The One with the Sonogram at the End - S1-E2
Visible crew/equipment: Ross stands up to tell his parents about what has happened with Carol. When he does he walks round the table and stands under a very visible boom microphone. (00:12:05)
The One with the Sonogram at the End - S1-E2
Continuity mistake: When Monica is asking if Ross has any stories to tell, she is looking at Ross and grinning. When the camera cuts, her expression has changed massively. (00:12:00)
The One with Mrs. Bing - S1-E11
Continuity mistake: When Coma Guy asks who Monica and Phoebe who they are, he has his hands lowered on the bed in one shot and raised outstretched in the next. (00:18:30)
The One with Mrs. Bing - S1-E11
Continuity mistake: The way Joey holds the picture of his mum changes between shots. Note his fingers. (00:15:50)
The One Where Underdog Gets Away - S1-E9
Visible crew/equipment: When Joey walks into Central Perk after the VD poster montage, a tape marker is visible on the floor behind Chandlers spot on the sofa. (00:10:40)
The One Where Nana Dies Twice - S1-E8
Continuity mistake: When Rach asks who the naked picture is of, the way she holds it changes between shots. (00:21:10)
The One Where Nana Dies Twice - S1-E8
Continuity mistake: At the funeral, Judy says to Monica that Nana would have hated this [the funeral]. When she does, Monica's arm changes position between shots. (00:18:50)
The One Where Nana Dies Twice - S1-E8
Continuity mistake: When Monica is talking to her dad at the table, the way he holds the magazine changes between shots. (00:08:50)
Continuity mistake: At the very end when Monica is in bed, her grip on the bed clothes changes between shots. (00:23:10)
The One with the Thumb - S1-E3
Visible crew/equipment: At the end, just as Monica walks off a tape marker can be seen on the floor where she was stood. This is as the credits are on screen. (00:22:30)
The One with the Sonogram at the End - S1-E2
Continuity mistake: When Barry is explaining how he is an orthodontist, he is holding a dental tool up. Camera cuts and now it's lowered. (00:19:30)
The One with the Thumb - S1-E3
Continuity mistake: When Monica ask's Ross if she looks OK, her hand is raised or by her side depending on the shot. (00:09:45)
The One with the Sonogram at the End - S1-E2
Continuity mistake: When Monica has her elbow on Ross' hand, her fist is under her chin. The camera changes to a different angle and now her hand is no longer under her chin and to the side of her jaw. (00:12:00)
The One That Could Have Been, part 2 - S6-E16
Continuity mistake: When Chandler goes into Monica's apartment after he beeps Dr Roger for a "ruptured spleen" his hair is sticking up through the front of his cap. After he tells Monica "You should be with me", the shot goes to Monica and when it goes back to him, his hair is neatly tucked into the cap.
The One with the Blackout - S1-E7
Audio problem: When Phoebe is counting down to the last candle burning out you can see Joey blowing out the candle, but the sound of his blow is only heard a second later after he sits back. (00:22:50)
The One With Ross's Grant - S10-E6
Continuity mistake: After Joey puts the video in the player, it's clear the video doesn't go all the way in, and even starts to eject itself. The shot cuts, and without him making any moves to replace the tape, it plays fine.
The One With The Princess Leia Fantasy - S3-E1
Continuity mistake: When Janice is talking to Joey about his disliking her, her long hair keeps changing position from hanging down her front to being behind her shoulders and down her back.
The One Where Ross Moves In - S5-E7
Revealing mistake: During Danny's party you can see Monica's apartment through the gap between the door and the wall, despite the party taking place on a lower floor. This is because they just reused the set for the hallway to save having to build a new set for the "lower floor."
