What are the functions of Head of government in a presidential system?

1. He assents to bills to become laws.
2. He appoints ministers and
   advisers which he could also dismiss.
3. He exercise the power of
   prerogative of mercy. 
4. He signs treaties on behalf of his
   country.
5. He initiates and implements
   government policies for his country. 
6. He is the commander -in-chief of
   the armed forces.
7. He could authorise the withdrawal
   of money from the consolidated fund. 
8. He is the representative of the
   country.
9. He could proclaim a state of emergency in the country
   or any part of it if there is a breakdown of law and order. 
10. He presents the annual budget to
    the legislature for its considerations.