Explanation
Expresses a conditional wish or unlikely possibility; 'if only', 'if it were possible'.
Formation
Verb-(potential/plain) form + ものなら, etc.
Detailed explanation
「～ものなら」 is used when expressing a strong wish under a hypothetical or difficult condition. It often implies that fulfilling this condition is unlikely or very hard, but 'if only it could happen, then...'.
Examples
Kaereru mono nara, ima sugu kuni e kaeritai.
If I could possibly go back, I'd return to my country right now.
Dekiru mono nara, sekai o isshuu shite mitai.
If it were possible, I'd love to travel around the world.
Yarinaoseru mono nara, kodomo no koro ni modoritai.
If I could redo my life, I'd go back to my childhood.
Genki ni nareru mono nara, donna kusuri demo tameshitai.
If it could make me healthy, I'd try any medicine.
Practice
Grammar content sourced from hanabira.org.