I am writing this letter in response to your ad regarding Portuguese lessons for your children. I believe your children could benefit from my expertise because I have been teaching for almost ten years and I have a Bachelor Degree in Portuguese. In addition, my fluency in English makes it easier to overcome any communication issues that we could face.
Considering the Portuguese classes as a part time job, I would be more than happy to help you and your wife in domestic chores and I could also assist the kids with their homeworks and activities. I undertand I may seem to eager for this job but, if I may be honest, I am really excited about a chance to work in Australia. It is a country that has fascinated me since I was little both for its breathtaking landscapes and diverse wild life so, to be able to live and work there for a year, is an amazing opportunity for me.
If you believe I can be a good fit for your needs, rest assured that I will give my best to attend your expectations. I hope to hear from you soon!
Warm regards! 
I am writing this letter in response to your ad regarding Portuguese lessons for your children. I believe your children could benefit from my expertise  
because
 I have been teaching for almost ten years and I have a Bachelor Degree in Portuguese.  
In addition
, my fluency in English  
makes
 it easier to overcome any communication issues that we could face.
Considering the Portuguese classes as a  
part time
 job, I would be more than happy to  
help
 you and your wife in domestic chores and I could  
also
 assist the kids with their  
homeworks
 and activities. I  
undertand
 I may seem to eager for this job  
but
, if I may be honest, I am  
really
 excited about a chance to work in Australia. It is a country that has fascinated me since I was  
little
 both for its breathtaking landscapes and diverse wild life  
so
, to be able to  
live
 and work there for a year, is an amazing opportunity for me.
If you believe I can be a  
good
 fit for your needs, rest assured that I will give my best to attend your expectations. I hope to hear from you  
soon
!
Warm regards!