(つら)

つらい
adjective (i-adjective)
hard, painful, difficult
1. hard, painful, difficult to bear
Describing something emotionally or physically difficult to endure. Expresses suffering or hardship.
(つら)(とき)
It's a hard time.
Work is hard/painful.
Expressing that work is difficult to endure
(わか)れる(つら)かった。
Parting was painful.
If something difficult happens, please talk to me.
Please don't keep your painful feelings to yourself. It's important to talk to someone.

(つら)い conjugates as an i-adjective: (つら)くない (negative), (つら)くて (te-form), (つら)かった (past).

Note: The kanji (つら)い can also be read からい (meaning spicy). Context usually makes the meaning clear. (つら)い (つらい) expresses emotional/physical hardship, while (から)い (からい) describes spicy taste.