Runaway Float / Partners - S2-E20
Continuity mistake: Runaway Float: The big beeper float constantly changes appearance during the parade. Some examples: The sign saying "Let's Go Downtown" on the front changes to "Let' Go Downtown" in one shot. The sign saying "Let's Go Downtown" on the back is missing in one shot. The orange base is sometimes blue. The blue city design around the base sometimes isn't there, and it even changes colour. (00:08:17)

Runaway Float / Partners - S2-E20
Continuity mistake: Runaway Float: When Arnold reaches the parade float on the bike, Iggy's shirt is incorrectly coloured green instead of purple. It's also green when the float rides past Mayor Dixie. (00:09:45)

Hall Monitor / Harold's Bar Mitzvah - S2-E15
Continuity mistake: Hall Monitor: After Phoebe's eyeglasses are stepped on, when she tells Helga, "Out with the old Phoebe, in with the new," Phoebe's belt buckle and two brown pouches have vanished, then reappear in the next shot. Later, while Phoebe sits on the desk during detention, her belt buckle is missing in her close-ups, and it reappears mid-shot as she crosses her legs. Then, when Phoebe's classmates share how they miss the "old" Phoebe, her buckle and the two brown pouches vanish, but they all reappear in a moment. (00:05:05)
Hall Monitor / Harold's Bar Mitzvah - S2-E15
Continuity mistake: Hall Monitor: In the first and last overhead shots of the detention classroom, the "fire" sign, the fire extinguisher, and light switch are not on the wall beside the door, though all are on the wall in other shots during this scene. (00:09:30)

Hall Monitor / Harold's Bar Mitzvah - S2-E15
Continuity mistake: Hall Monitor: While Phoebe is hall monitor, her watch repeatedly disappears and reappears on her wrist, even mid-shot. (00:05:00)
Hall Monitor / Harold's Bar Mitzvah - S2-E15
Continuity mistake: Hall Monitor: When Principal Wartz tells Helga she cannot volunteer again, he removes the "revered badge" and its black crossbody strap from Helga. Helga then selects Phoebe as the next hall monitor. When Phoebe joins them on the stage, Helga is again wearing the crossbody strap with the badge in the wide shot, but it's gone in the next shot as Wartz places it on Phoebe. (00:02:10)
Hall Monitor / Harold's Bar Mitzvah - S2-E15
Continuity mistake: Hall Monitor: During the school assembly, Principal Wartz's necktie has diagonal stripes, and its top knot stripes switch to the opposite direction, then revert to the proper direction.
Hall Monitor / Harold's Bar Mitzvah - S2-E15
Continuity mistake: Hall Monitor: While Helga is hall monitor, her watch repeatedly disappears and reappears on her wrist.
Helga's Locket / Sid and Germs - S5-E7
Continuity mistake: Helga's Locket: When Abner takes the locket from Helga at the end, Helga chases after him. In the next shot, they are shown running past the basement window of the boarding house, but that's impossible because they started running away from the basement window in the previous shot. (00:11:42)

Helga's Locket / Sid and Germs - S5-E7
Continuity mistake: Helga's Locket: After Helga leaves the boarding house through the basement window at the end, when it shows a close-up shot of the locket in her hands, Helga's sleeves are way longer than they should be. (00:11:37)
Helga's Locket / Sid and Germs - S5-E7
Continuity mistake: Helga's Locket: When Arnold and Grandpa are in the basement trying to pry open the locket, the tools on the workbench constantly rearrange themselves in various shots. (00:10:06)

Helga's Locket / Sid and Germs - S5-E7
Continuity mistake: Helga's Locket: When Arnold is cutting a photo of Grandma in his room, there is nothing on his computer screen. Then, when Arnold starts to leave his room, a photo of Lila appears on the screen. (00:05:48)

Girl Trouble / School Dance - S3-E18
Continuity mistake: Besides the fact that when Helga is sharpening her pencil, the desk arrangement changes, one of the students visible when she looks at Arnold is... Helga. This happens because the shot is taken from the episode "Helga's Love Potion."
Longest Monday / Eugene's Pet - S2-E4
Continuity mistake: In "Longest Monday" at one point in the episode, Arnold and Gerald run off of a bus and down an alley. Two fifth graders come chasing after them. In the next scene, you see Arnold and Gerald hiding in the sewer under the 5th graders. Arnold then crawls through a very narrow tube, and Gerald follows. You then see the end of the tube and Gerald come out of the it first, and Arnold climbs out last. It would be impossible for Arnold and Gerald to switch places inside the tube because it was way too narrow.

Mud Bowl / Gerald Moves Out - S2-E9
Continuity mistake: When Gerald catches his little sister destroying his cassette tape, the book she is wrapping changes color from blue to green. (00:12:30)

Continuity mistake: When the four boys form their line (just before the adults call out "Arnold"), watch Harold's tooth; it goes from the right side of his mouth (as you look at him) to his left side.

The Little Pink Book/Field Trip - S1-E2
Continuity mistake: On the "Presidents of the United States" sign behind Helga, the word "United" becomes "Nvited"

Arnold's Hat/Stoop Kid - S1-E3
Continuity mistake: When Grandpa is telling Arnold about how how he tried to cover his head when his hair falls out, the camera cuts back to him with his arm on Arnold's shoulder and Arnold has his hat on, even though the whole story is about him losing his hat.

Continuity mistake: Phoebe is going into the school in one scene, but as the camera moves she vanishes while on screen.

Parents Day - S5-E6
Continuity mistake: In the scene where Arnold's parents leave for the last time, Grandma's hair is dark at first, then it becomes purplish-gray.
Answer: No, he did not. He is seen getting off the bus with a suitcase, so he must have not been home for a few days so there is no way he could have known.
Bowling255 ★