also: もんなら
expression
if I could; if we could
Expresses a hypothetical wish or desire, often with a sense of 'if only I could...'. Follows the volitional form of a verb (e.g., 行けるものなら).
行けるものなら、もう一度あの場所に行きたい。
If I could go, I'd like to visit that place one more time.
やれるものならやってみろ。
If you can do it, just try.
expression
if one were to ... then ... (unpleasant result)
Used in the pattern ...うものなら, ...ようものなら, or ...まいものなら. It implies that if someone dares to do something, a bad consequence will follow. Often carries a warning or threatening tone.
彼に逆らおうものなら、すぐに首になるだろう。
If you dare to defy him, you'll probably be fired immediately.
そんなことを言おうものなら、彼女は怒り出すに違いない。
If you were to say such a thing, she would definitely get angry.
A simple conditional particle meaning 'if'. ものなら adds a nuance of hypothetical desire or warning, often with a volitional verb.
A general conditional form. ものなら is more specific and often implies a strong hypothetical or a threatening outcome.
Derived from the noun もの (thing) and the conditional particle なら (if). The combination grammaticalized into a fixed expression meaning 'if one could' or 'if one were to...'.