Thank you Obrigado Obrigahdu – only said by males
  Obrigada Obrigahda – only said by females
 
Thank you very much Muito obrigado/a M[ng]wee[ng]tu Obrigahdu/a 

*Re: Obrigado/obrigada:  In some regions, particularly the Algarve, it is common for both men and women to use both obrigado and obrigada - switching between them depending on the gender of the person they are talking to.  This is technically incorrect because the word ’obrigado’ is an adjective which is describing the person speaking - it literally means ’obliged’.