General sadness:
* 伤心 (shāng xīn) - This is the most common and general way to say "sad".
* 难过 (nán guò) - Similar to "伤心", this also means "sad" but can also convey a feeling of being distressed or heartbroken.
More specific emotions:
* 沮丧 (jǔ sàng) - This implies a feeling of discouragement or dejection.
* 失落 (shī luò) - This describes a feeling of loss or emptiness.
* 哀伤 (āi shāng) - This is a more formal and poetic way to say "sad", often used to express grief or sorrow.
In addition to these, you can also use phrases like:
* 心情不好 (xīn qíng bù hǎo) - Literally "mood is not good"
* 感觉很糟糕 (gǎn jué hěn zāo gāo) - Literally "feeling very bad"
The best way to choose the right word or phrase depends on the specific situation and how you want to express your sadness.