What’s the difference between “flammable” and “inflammable”?

They mean the same thing! Both “flammable” and “inflammable” mean “easily set on fire.”

📜 History: “Inflammable” comes from Latin “inflammare” (meaning “to set on fire”), where “in-“ does NOT mean “not” but instead “into” or “cause.” However, English speakers mistakenly thought “inflammable” meant “not flammable,” so “flammable” was introduced to avoid confusion.

🤔 Trivia: Similar words exist, like “valuable” and “invaluable,” which both mean “highly valuable.”