Stuart asked: "Could we not also say "une valeur sûre" as well as "une valeur certaine"? "

Question

Sa collection de tableaux a une ___ . (His painting collection has sure value.)

Accepted Answer

Bonjour Stuart !

That's an interesting case!
Indeed, "une valeur sûre" could seem to be a possible synonym here for "une valeur certaine", however they don't actually mean the same thing in French.
​
​Look at this sentence: 
"Fais-moi confiance, c'est une valeur sûre !"   (Trust me, it's a safe bet / a sure thing / a valued asset!)
​Note that you use it with "être", and would never say "avoir une valeur sûre".

I hope that's helpful!
À bientôt !

Answer

Bonjour David !
I looked at the examples you provided and:
On a une valeur sûre avec Lisa Angeli.   -> Here it's the same case I mentioned, where it means she is a reliable talent for these people. This sentence means that "they have a reliable winner in her."
As for the other examples, I must admit that they seem valid, though I've never used this expression like this myself.
I will therefore amend the question to accept both answers :)
Merci et bonne journée !

Answer

Hi Aurélie,
That's a tricky point; I think most anglophones would use the two (certain , sure) interchangeably.  You might consider integrating it in a quiz or placing a note in one of the lessons.
Keep up the good work !

Answer

Here are examples of French speakers using "une valeur sûre" with avoir:
https://www.public.fr/Public-TV/Scoop-Public-TV/Exclu-Video-Stephane-Bern-Eurovision-2015-On-a-une-valeur-sure-avec-Lisa-Angell-730072

http://www.alterinfo.net/L-arnaque-de-la-recuperation-des-bijoux-en-or-par-des-operateurs-financiers-prives_a55634.html
(Comment #29)

https://vancouver.consulfrance.org/Notariat-et-legalisations-de-signature-Procedure