诉苦 (sù kǔ): 불평하다.

She is under a lot of work pressure, and every day after work she vents to a good friend, who always listens patiently to her complaints.

His boss has been criticizing him a lot lately, and he felt wronged, so he complained to a colleague that he wanted to quit.

The neighbor's dog barks nonstop every night, and she couldn't stand it anymore, so she had no choice but to complain to the property management.

While he was hospitalized, many friends came to visit him, and he couldn't help but complain to them that the hospital food was terrible.

Mom works hard doing housework every day, yet she never complains to the family and always silently bears everything.