As many episodes and times you have watched Friends, you might have never seen these filming mistakes. Check out 10 hilarious filming mistakes from Friends below to see what I mean!
1.Joey's Shirt Changes Colors.
In "The One With Rachel's Inadvertent Kiss," Joey counts the floors to Ross' building to find out where "Hot Girl" lives. At first he's wearing a black top, but in the shots where he knocks on what he thinks is the girl's door, he's wearing a purple shirt.
在第5季第17集（The One With Rachel's Inadvertent Kiss），乔伊数着楼层门牌号，来到了罗斯所住的公寓楼，想找到“漂亮妹子”住的那件房。一开始他穿着一件黑色上衣，可是当镜头切换到他去敲他自以为是妹子家的门时，他穿的却是紫色衬衫。
When Ross opens the door, his black shirt is revealed again.
In "The One With The Mugging," Joey grabs a bunch of beverages to keep his bladder full for an audition.
在第9季第15集（The One With The Mugging），乔伊拿来一堆饮料，想把自己喝得饱饱的，好在试镜时超常发挥。（据说憋尿会让表演更富激情……）
When the scenes change and go back to Joey with his hands full, the beverages change and he's no longer holding sodas in his hand.
3.Stain Be Gone.
In "The One With The Late Thanksgiving," Joey appears on camera with a very distinct stain on his shirt...
在第10季第8集（The One With The Late Thanksgiving），乔伊出场时，衣服上有一块明显的污迹。
In the very next shot, the stain seems to change positions and is considerably less visible.
In "The One With the Male Nanny," Sandy is doing a puppet show with a blue and yellow puppet on each hand.
在第9季第6集（The One With the Male Nanny），男保姆珊迪用一只蓝色手偶和一只黄色手偶表演了一段手偶秀。
In between scenes going back to Ross and Sandy, the puppets switch hands.
5.Where Do They Live Again?
Throughout all of season 1, the number on the door for Monica's apartment constantly changes.
Producers realized that apartment numbers "4" and "5" was for bottom floors so after acknowledging this mistake, they soon corrected it and changed the numbers of the boys' and girls' apartments to "19" and "20."
In "The One With a Chick And a Duck," Pete is talking to Monica at her work while she is on roller skates. In the scene, she eventually falls from being clumsy while skating but the camera catches the landing mattress that Monica falls on to protect her.
在第三季第21集（The One With a Chick And a Duck），莫妮卡正在上班，皮特跟她说话，此时她正穿着一双旱冰鞋。在这个场景中，她因为滑冰技术不佳滑倒了，可是摄像头却拍到了安全气垫，这个气垫是剧组人员为了在莫妮卡摔倒时保证她的安全而铺设的。
7.Clearly in a Set.
In "The One With Ross's Grant," when Joey goes to turn off the television the edge of the set is visible on the blank screen.
在第10季第6集（The One With Ross's Grant），乔伊转身去关掉电视机时，电视机的黑屏幕上可以看到摄影棚的一角。
In "The One With Princess Consuela," Mike and Pheobe are talking about their two new goofy name changes when Mike's scarf seems to magically tie itself. In one scene it's open...
在第10季第10集（The One With Princess Consuela），麦克和菲比谈到他们想换两个逗比的名字，这时麦克的围巾神奇地给自己打了个结。在一个镜头里它是自然垂下的……
...but when the scene cuts back from another angle, his scarf is tied.
In the episode "The One Where Ross Finds Out," Rachel is talking to Ross and Julie about getting a cat when a necklace begins to appear and disappear randomly.
在第2季第7集（The One Where Ross Finds Out），瑞秋正在和罗斯和朱莉这对爱侣一起讨论要不要养只猫咪，这时她的项链开始任性的时隐时现。
In one scene it's missing and as the camera pans back to Rachel it's clearly visible again.
In "The One With The Bullies," Phoebe is chased back to her car by a little Jack Russell terrier. The scene is supposed to display the sarcastic "viciousness" of the dog as he jumps in the window to bark, but you can clearly see the top of the head of the dog handler to make sure the dog is okay.
在第2季第21集（The One With The Bullies），菲比在一只杰克罗素㹴小犬的追逐下躲进了车里。这个场景的本意是想诙谐的表现狗狗的“邪恶”，可是当狗狗跳上车窗开始吠叫的时候，你能清楚的看到训犬员的头，可见有训犬员确保它的安全。