Dear Mrs Black,
I am writing to you because I have found the advertisement you announced.My name is XYZ and I think I am a good person as concerns babysitting.I consider myself to be reliable and responsible and I love children. I have good contact with them.I am going to study English at the language school for a year.I think I could share my time with children everyday since afternoon and at weekends.
I would like to know what would belong to my duties and what accomodation conditions I could expect in return for looking after your children.
Would you mind telling me if I will be getting pocket money?
I am looking forwarad to hearing from you.I am ready to any your questions.