辛い
からい · karai · JLPT N5 · i-adj
hot and spicy
🌶️ karai sounds like curry: spicy curry is karai
Karai is close to the English word curry, a dish known for heat. The kanji 辛 also reads tsurai (painful), so the same character covers a burning tongue and a hard time. Older usage extends karai to salty, as in shiokarai.
つらい · tsurai · JLPT N3 · i-adj
painful
🩹 Tsurai sounds like so sorry, what you say when something is painful
The kanji 辛 began as a needle used to brand criminals, so pain is built into it. Read からい (karai), the same kanji means spicy: pain on the tongue. Read つらい (tsurai), it means pain in the heart.