be as stubborn as a mule

US /bi æz ˈstʌbərn æz ə mjuːl/
UK /bi æz ˈstʌbərn æz ə mjuːl/
"be as stubborn as a mule" picture
1.

ser terco como una mula, ser muy obstinado

to be very stubborn and unwilling to change one's mind or opinion

:
You can try to convince him, but he'll be as stubborn as a mule.
Puedes intentar convencerlo, pero será terco como una mula.
My grandfather used to be as stubborn as a mule when it came to new technology.
Mi abuelo solía ser terco como una mula cuando se trataba de nuevas tecnologías.