De peur que + ne explétif + Le Subjonctif = For fear that

Question

My reflexive response to translation of 'We opened the windows out of fear there might be a gas leak.' was 'Nous avons ouvert les 
fenêtres de peur qu'il ne puisse y avoir une fuite de gaz.' given that 
there is a sense of conditional pouvoir in the translation ('there could 
be or 'might be', rather than the softer 'we're not sure' sense of avoir 
in the subjunctive. Any thoughts?

Céline Pickard · Accepted Answer

Bonjour John,
Your answer is grammatically correct and in a everyday conversation it would be perfectly acceptable. However, if 'there could be' was expected, a hint asking to use 'pouvoir' would have been displayed so as to avoid any ambiguity. As there is none, the expected answer is simply to use 'there might be' (= qu'il n'y ait). 
I hope this is helpful.
Bonne journée !