Breakdown of Ils doutent que la provenance soit authentique, alors ils demandent une expertise.
être
to be
un
a / an (masculine)
ils
they (masculine/mixed)
alors
so, then
Questions & Answers about Ils doutent que la provenance soit authentique, alors ils demandent une expertise.
Why do we use the subjunctive soit after douter que?
The verb douter expresses uncertainty or doubt, which triggers the subjunctive mood for the following verb. We use soit (the subjunctive of être) because the authenticity of the provenance is in question, not a stated fact.
How would the grammar and meaning change if we used se douter que instead of douter que?
It would change completely! While douter que means "to doubt that" and takes the subjunctive, the reflexive se douter que means "to suspect that" or "to have a hunch that". Because it expresses a strong belief rather than doubt, it takes the indicative. The sentence would become Ils se doutent que la provenance est authentique (They suspect that the provenance is authentic).
Doesn't "to ask for" usually involve a preposition? Why is it just demandent une expertise?
Is une expertise a false friend here?