Revealing: Before Phoebe agrees to carry Frank and Alice's' triplets, she already has a baby bump.

Continuity: When Chandler, Joey and Monica tell their story of the jellyfish bite Chandler says sometimes at night he still hears Joey's voice screaming "Do it ! Do it!". Joey says he yells it through the wall at night to freak Chandler out, but no nights have passed. They tell the story the same day the jellyfish bite occurred. Notice Rachel, Ross and Phoebe are wearing the same clothes they had before they left the beach house.

Audio problem: When Phoebe is knocking on her sister Ursula's door to tell her about finding her birth mum, the third knock is heard a split second before you see Phoebe's hand action.

Continuity: Phoebe and her mother are in her mother's house at the beach. Phoebe has just found out that Phoebe senior is her real mother. Have a look at Phoebe's mother in this episode and the last episode of series 3 (The One at the Beach). Her hair is a lot shorter in series 4 even though no time has passed in the storyline.

Visible crew/equipment: When Ross storms out of the room and the rest of the friends are in the kitchen, you can see the stage lights at the top of the screen.

Continuity: In Joanna's office, Chandler and Rachel are pulling his pants from one another while he is cuffed to the filing cabinet. Right before Rachel says "What if I clean your bathroom for a month?" she throws the pants onto a chair, but then when Chandler later says "Freedom. I want my freedom. Why won't you hear me?" he opens the door to yell to Sophie and they are both holding the pants again.

Continuity: Joey's encounter with the encyclopedia salesman is riddled with errors. First, when the salesman is talking about Van Gogh and saying "He painted that," he points to a page that is all text; later, Joey is reading about vomit, and it is at a pont much further on in the book than when the salesman read about vulcanized rubber (which it shouldn't be, given the encyclopedia is alphabetized); finally, when Joey buys the "V" volume, as he opens it he has a $50 bill in his hand, and when the shot changes to show the salesman he is somehow folding and pocketing it without having taken it from Joey.

Continuity: In the Central Perk scene when Joey is telling Monica and Rachel about the dancing, Monica's legs are crossed left over right and then right over left, and back again.

Other: Right at the end of the episode, Phoebe's got a job interview. We see the outside of a massage parlour, but the name on the awning has been superimposed - it moves about a bit while the shot itself is still.

Other: In the scene where Rachel is going to take out the trash, Monica tells her the garbage room is the 3rd door on the left. However, when Rachel comes back with the pizza box and Monica leaves for the garbage room, she leaves the apartment and walks towards the right - there are no doors that way, just the stairs.

Audio problem: In the sequence where Chandler chases Kathy down the street, there is a moment, shortly after he walks into the man with the hotdog, where he shouts her name, but his lips don't move at all.

Continuity: Chandler is chasing Kathy down the street trying to get her attention. During a close-up of him running, just before the camera cuts away we see a guy's face on the left; when it cuts back to Chandler he runs for a while and then encounters the same guy (the dog-walker). Also, when he finally lands in front of Kathy, there is a bike rider coming towards them, but as the camera cuts back and forth between the two, the rider never passes them.

Continuity: During the scene where Chandler is playing hide and seek with the duck and the chick, the duck moves from facing the opposite way to him, facing the same way, and then the opposite way as Joey walks in.

Continuity: In the bar, Cathy is trying to set Chandler up with one of her friends. When the camera is facing Chandler, we see Cathy's hand rubbing Joey's back, but when it cuts to a front shot of Joey and Cathy, her arm is down in front of her. Then without having had enough time to move, her elbow is up on the table and she is holding hands with Joey.

Continuity: When Chandler is chasing Cathy, the mustard on his shirt changes place, size and darkness throughout the scene.

Visible crew/equipment: When Rachel says, "And not a coupon for an hour of Joey love," the stage lights are reflected in the tv.

Visible crew/equipment: When Monica leaves the kitchen into the next scene, the boom mic is visible at the top of the screen above the kitchen door for a short period of time.

Continuity: At the beginning of the episode where they are watching Ross through the window, Phoebe is leaning forward and standing to the left of the pole next to Chandler. When the shot changes to Ross coming through the door, she is suddenly standing up straight and is now behind Joey and Chandler.

Continuity: Towards the end of the episode, when Chandler comes into the apartment to talk to Joey about his kiss with Kathy, Joey turns the TV off and places the remote on the counter. However, the TV is suddenly back on after Joey asks, "Is that why you bought all this stuff?" (referring to the furniture}, and then Joey turns it off again manually.

Continuity: When Phoebe tells Ross that she wants to hear his "sound", she has her guitar in her lap. The shot changes, she says "Play that funky music white boy," and her guitar is missing. In the next shot, Ross runs out and her guitar is back on her lap again.