References: :-

• Oscar fernádez, Portuguese coursebook, Living language, A reader home company/ 2002.
• Http://www.verba.org/verbi/all_verbs_index-pt.html
• http://www.verba.org/owa-v/verba-dba.verba-main.create-page lang=en;
• http://www.goethe-verlog.com/tests/EP/EPT010.htm
• Collins Pocket English-Portuguese Português-Inglês Dictionary./collins/2001.
• Ipor (Institute of Portuguese Of the orient)
• University of Coimbra
• Dictinario de verbos Português.
• Dictinario de verbos Português 2 breve gramatica contemporaneo.
• Language course- Hugo.
• http://www.w3schools.com