French phrase
En supposant que ~.
Meaning
Assuming that ___.
When to use it
Sets out a condition as a premise for what follows. It is neutral and usable in everyday or somewhat formal contexts.
Example dialogue
On annule le pique-nique ?
Should we cancel the picnic?
En supposant que la météo soit mauvaise demain. Il vaut mieux prévoir un plan B.
Assuming that the weather will be bad tomorrow. We'd better prepare a backup plan.