The character 假 is a perfect example of a polysemous character (多音字 duōyīnzì), a single character with multiple pronunciations and meanings.
Reading 1: The “Fake” 假
Reading 2: The “Vacation” 假
You can create a simple mnemonic to remember both meanings: A person (亻) can “borrow” an identity, making it fake (jiǎ). A person (亻) can also “borrow” time away from their job, giving them a vacation (jià).
The two meanings of 假 tap into very different, but equally important, aspects of Chinese culture.
Understanding when to use which pronunciation is key.
Using “jiǎ” (Fake) This is most often used as an adjective, frequently with 的 (de).
Using “jià” (Vacation) This is a noun that almost never stands alone. It's always part of a verb-object phrase or a compound noun.
Examples for 假 (jiǎ - fake)
Examples for 假 (jià - vacation/leave)