Family Ties (1982)

Dear Mallory - S6-E3

Continuity mistake: Mallory starts reading one of her advice column letters to Alex. The letter she pulls from the stack is on blue paper in a blue envelope. After a cuts to Alex, there's a close-up of Mallory as she reads the letter, and then in the next wide shot the letter is on orange paper with an orange envelope. The letter is from a girl who intrigues Alex, so he grabs the orange envelope and starts to tear off the return address. The shot changes to show Elyse walk into the room, and Alex is now tearing the corner from the original blue envelope. When Elyse sits down, Alex reads the address holding a slip of the blue envelope, then starts to get up. In the immediate cut that follows, Alex is holding the orange envelope when he stands up. (00:53:50 - 00:54:55)

Vader47000

Little Man on Campus - S3-E3

Continuity mistake: In Alex's government class, the professor wrote "Free Speech" on the chalkboard. In a few of the following shots the handwriting differs, and in some shots the phrase is underlined, but in other shots, it is not underlined. (00:05:00)

posty

The Real Thing: Part 2 - S4-E2

Continuity mistake: In the previous episode Jennifer sees Ellen Reed for the first time while talking to Alex (when Alex is holding Andy). In this episode, she sees Alex viewing picture of Ellen and asks "who is Ellen Reed?" as if she had never seen her before. (00:12:10)

Say Uncle - S2-E14

Continuity mistake: When Alex tells Jennifer to play her clarinet outside Jennifer complains that its dark out, but you can see through the window that it is bright out. When they show it again it is dark.

Fool for Love - S4-E15

Continuity mistake: In this episode, Mallory and Skippy are talking and Mallory starts a sentence with "remember when we were 2 years old..."? This is incorrect as an earlier season had an episode in a flashback when the Keatons just moved into their house and the kids were young and Skippy meets Mallory for the first time and instantly falls for her. Both Skippy and Mallory were about 5 or 6 years old in the scene so knowing each other at 2 years old was not possible.

Speed Trap - S2-E6

Continuity mistake: When Alex falls asleep after he and Steven are talking in the room about the dangers of the pills, there is an alarm clock on the nightstand next to the bed. Next scene, the parents come in and wake up Alex and suddenly the alarm clock disappears and is nowhere to be seen anywhere around.