French phrase
Je ne suis pas certain, mais ~.
Meaning
I'm not certain, but ___.
When to use it
A polite way to signal uncertainty. It is useful when withholding a firm judgment and gently encouraging verification.
Example dialogue
On peut lancer la production cette semaine ?
Can we launch production this week?
Je ne suis pas certain, mais il vaudrait mieux vérifier la disponibilité des matières premières.
I'm not certain, but it would be better to check whether the raw materials are available.