犟劲

tā jiàng jìn yī shàng lai shuí dōu quàn bu zhù

他犟劲一上来，谁都劝不住。

No one can stop him when his mind is made up.

tā de jiàng jìn yī shàng lai jiǎn zhí zhí niù de yào mìng

她的犟劲一上来，简直执拗得要命！

She can be very obstinate when she wants to be!