You met reasoning about causes earlier. When that reasoning skips the checks, it becomes a fallacy.
Key idea
False cause claims that one thing caused another only because it came first (often called post hoc, "after this") or only because the two happen together.
Why it works
Many things come before any event, and many things move together by chance or because of a third cause. Timing is a clue to look further, not a proof. Good causal claims rule out the other explanations.
Worked example: After, so because?
"Kai started drinking orange juice every morning, and a week later the cold went away. So orange juice cured the cold."
- Colds usually clear up in about a week on their own.
- The timing fits, but it would fit without the juice too.
Answer: False cause.
Worked example: Together, so because?
"Ice cream sales and sunburns rise in the same months. So ice cream causes sunburn."
- Could something else cause both? Yes: hot, sunny weather.
- People buy more ice cream and get more sunburns on sunny days, so neither needs to cause the other.
Answer: False cause.
Common mistake
Accepting "it happened right after, so it caused it." Before agreeing, look for other causes (what else changed?), reversed direction, and plain chance.