忍不住 + Verb
忍不住 (rěnbuzhù) is a verb meaning "can't help but" or "can't resist." It combines 忍 (rěn, "to endure") with the negative potential complement 不住, indicating that one is unable to hold back an action or emotion, such as laughing, crying, or speaking out.
她忍不住笑了出来。
Tā rěn bù zhù xiào le chūlái.
She couldn't help but burst out laughing.
看到那只小猫,我忍不住想摸一摸。
Kàndào nà zhī xiǎo māo, wǒ rěn bù zhù xiǎng mō yī mō.
Seeing that little cat, I couldn't resist wanting to pet it.
他忍不住问了一句:你还好吗?
Tā rěn bù zhù wèn le yī jù: nǐ hái hǎo ma?
He couldn't help but ask: "Are you okay?"