or

Meaning

Introduces the FACT THAT TIPS the argument, often just before the conclusion.

Position and punctuation

at the start of the sentence · a comma after

Example

Ce dispositif devait réduire les délais. Or, les chiffres publiés montrent l'inverse.

This scheme was meant to cut waiting times. Yet the published figures show the opposite.

In the DELF

the C1 synthesis

The trap

Or is not a plain mais: it is the second step of a three-step argument (you state, or you object, donc you conclude). Using it with no conclusion leaves the sentence hanging.