Kate McCann has promised her missing daughter Madeleine: "We will never give up until we've found you."
Speaking ahead of the third anniversary of the little girl's disappearance, Mrs McCann and her husband Gerry McCann urged their daughter to tell someone who she is and assured her they would not stop searching for her.
In an emotional address to her daughter, Mrs McCann, 42, said: "We love you very much, Madeleine, and we're not going to stop what we're doing."
The couple do not know what their daughter might have been told about them or what language she might be speaking now, they said.
Mr McCann, 41, said the message he wanted to give her was: "Madeleine, we're still looking for you. Tell someone who your mummy and daddy are, who you are."
The couple remain determined to find her but now feel less guilty about coping and enjoying themselves without her.
Mrs McCann said: "I'm able to look at it now and think actually it's positive we're functioning. It's positive for Madeleine and for (her siblings, five-year-old twins) Sean and Amelie and unless you're in this situation you have absolutely no idea how you cope."
Neither can imagine a time when they would give up the search - although they are currently receiving little new information and progress is slow.
Mr McCann said: "There are several active lines of inquiry but we have to be realistic. We do not have the same ability to follow up lines of inquiry that the police do.
"A lot of our focus now is on working with the British and Portuguese authorities and saying it's not good enough to have stopped and to have essentially given up."