I wouldn't have … it
À votre place, je ne l'aurais pas fait.
If I were you, I wouldn’t have done it.
Je ne l'aurais pas fait tout seul.
I wouldn't have done it on my own.
I wouldn't have done it.
Si je l'avais noté, alors je ne l'aurais pas oublié !
If I had written it down, I wouldn't have forgotten it!