To stop doing something, parar, dejar or either

To stop doing something, parar, dejar or either
 

Do both parar and dejar work?

If you don't stop yelling I won't give you back your toy.

Si no pares de gritar no te devolveré tu juguetón.

Si no dejes de gritar .....

If the both work is one favoured over the other?

Si no paras de gritar ...
Si no dejas de gritar ...

¿Dónde dicen "juguetón" por juguete? Juguetón significa playful.

ups on both counts, yes quite right, thanks