Simmons' Documentary / Big Bob's Crisis - S5-E20
Other mistake: Big Bob's Crisis: When Bob faints at the restaurant and first appears as an angel, his eyes become the same colour as his skin twice. (00:13:58)
Simmons' Documentary / Big Bob's Crisis - S5-E20
Other mistake: Big Bob's Crisis: When Bob faints at the restaurant and first appears as an angel, his eyes become the same colour as his skin twice. (00:13:58)

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."
The Aptitude Test / Oskar Gets a Job - S3-E9
Suzie: I gave you 100 dollars two days ago.
Oskar: Suzie, you know I had to use it to pay the phone bill.
Suzie: Oskar, they cut off our phone service this morning.
Oskar: I know, it's a terrible mistake. We should sue.
Suzie: Oh, Oskar, that just doesn't make any sense.
Oskar: Tell me about it. So, can I have the 50 dollars?
Suzie: I don't have 50 dollars, we've already spent my paycheck this week.
Oskar: What about your overtime?
Suzie: I work 20 hours a week overtime already, how many more hours do you want me to work?
Oskar: How about 25?
Suzie: OSKAR!

Freeze Frame / Phoebe Cheats - S2-E8
Trivia: Arnold's computer is made by Purdy Electronics; Joseph Purdy wrote the episode.
Question: Does anybody know what year this show takes place? I've noticed that there are all these present day video games, keyboards, etc. on the show, but all the cars are old fashioned.
Answer: The show is based in present day times. Plus most cars aren't old fashtioned, I recall seeing a limo and not to mention a cherry picker, etc.