stay behind
US /steɪ bɪˈhaɪnd/
UK /steɪ bɪˈhaɪnd/

1.
quedarse, permanecer
to remain in a place after others have left
:
•
I had to stay behind to finish my work.
Tuve que quedarme para terminar mi trabajo.
•
The teacher asked a few students to stay behind after class.
El profesor pidió a algunos estudiantes que se quedaran después de clase.
2.
quedarse atrás, rezagarse
to make less progress than others
:
•
If you don't study, you'll stay behind in class.
Si no estudias, te quedarás atrás en clase.
•
The company is afraid it will stay behind its competitors if it doesn't innovate.
La empresa teme quedarse atrás de sus competidores si no innova.