Aide, Lettre en Anglais

Bon voilà,je dois écrire une lettre en Anglais voici se que j'ai fait:

Dear sir or Madam,

I am writing in response to your job announcement on the net for baby-sit your little son Kemaal and learn the french by playing.
I am 16 years old and I am in High School,so I can looking your son on saturdays,because I don't study on week-ends.
I am interested in this job because I love to keep babies and I would really enjoy being in contact and learn french while playing with them.
I have already looked after babies,I think which I would be very efficient,caring and responsible.So I think I would be great for this job.

Thank you for your time and attention
Sincerely,

Des conseils,des fautes ? Help me je suis pas très forte en Anglais. Evil or Very Mad

Salut,
Je dois faire la même lettre moi aussi.Alors je pense que les fautes sont:
IN the net for baby-sit your little son Kemaal and learn the french by playing.
learn TO HIM french by playing.
I can WORK on saturdays,

A plus

Si tu veux je peux te passer ma lettre c'est le même sujet.
J'attends ta réponse Smile

Oui ! Et merci pour les fautes. ^^

J'attends ta lettre Neutral