我常用微笑掩饰心底的悲伤
[wŏ cháng yòng wēi xiào yăn shì xīn dĭ de bēi shāng]
Expressed in English: 'I often use smiles to hide the sorrow in my heart.' This conveys the idea of wearing a cheerful face when feeling sadness inside, highlighting an inner conflict or the will to conceal one's true emotions.