you should be careful
Deberías tener cuidado a la hora de escoger a tus amigos.
You should be careful when choosing your friends.
You should be careful.
Deberías tener cuidado con lo que dices.
You should be careful what you say.
Yo pienso que deberías tener cuidado.
I think you should be careful.
Deberías tener cuidado con esas cosas.
You should be careful with those things.
Deberías tener cuidado con los baches cuando conduces.
You should be careful of potholes when you drive.