how dangerous it is
Sé lo peligroso que es Tom.
I know how dangerous Tom is.
No puedes ni imaginarte lo peligroso que es equivocarse aquí.
You can't even imagine how dangerous it is to make a mistake here.
— Stalker (1979)
Tal vez deberías recordar lo peligroso que es Tom.
Perhaps you should remember how dangerous Tom is.
I can see how dangerous it is.