por Randy Johnson » 07 Mar 2010, 12:49
Lucimar, "ensure" and "assure" are interchangeable in many contexts where they indicate making an outcome certain and inevitable.
"Ensure" may also imply a virtual, absolute guarantee (ex: The government has ensured the safety of the refugees.).
"Assure" implies the removal of doubt from a person's mind (ex: I assure you the report will be finished by the end of the day.),
I hope this helps.