August 5, 2003


John Hancock Sovereign Bond Fund
101 Huntington Avenue
Boston, MA 02199

Re:      John Hancock Sovereign Bond Fund (the "Trust") on behalf of:
          John Hancock Bond Fund (the "Fund")
         File Nos. 2-48925; 811-2402   (0000045288)
         -----------------------------------------


Ladies and Gentlemen:

In connection with the filing of Post Effective Amendment No. 54 under the
Securities Act of 1933, as amended, and Amendment No. 37 under the Investment
Company Act of 1940, as amended, for John Hancock Sovereign Bond Fund it is the
opinion of the undersigned that the Trust's shares when sold will be legally
issued, fully paid and nonassessable.

In  connection  with this opinion it should be noted that the Trust is an entity
of the type generally known as a  "Massachusetts  business trust." The Trust has
been duly organized and is validly  existing under the laws of the  Commonwealth
of  Massachusetts.  Under  Massachusetts  law,  shareholders  of a Massachusetts
business trust may be held  personally  liable for the obligations of the Trust.
However,  the Trust's Declaration of Trust disclaims  shareholder  liability for
obligations of the Trust and indemnifies  the  shareholders of a Fund, with this
indemnification to be paid solely out of the assets of that Fund. Therefore, the
shareholder's risk is limited to circumstances in which the assets of a Fund are
insufficient to meet the obligations asserted against that Fund's assets.


                                       Sincerely,


                                       /s/Brian E. Langenfeld
                                       ----------------------
                                       Brian E. Langenfeld
                                       Attorney and Assistant Secretary