不由得 (bù yóu de): can't help; cannot but

Hearing this familiar melody, she couldn't help but think of the friends she used to sing with during her university days.

Seeing her child stand up and walk on his own for the first time, the mother couldn't help but shed tears of excitement.

His joke was so funny that even the usually serious Teacher Wang couldn't help but laugh.

Standing at the top of the mountain and looking at the beautiful sunrise, I couldn't help but marvel at the greatness of nature.

Hearing that sad news, everyone present couldn't help but lower their heads and remained silent for a long time.