Pourquoi faire? = What for?
Comment faire? = What is to be done?
Que voulez-vous que j’y fasse? = How can I help it? What would you have me do? It is no business of mine.
Je ne saurais qu’y faire = I cannot help it.
A chose faite point de remède = What is done cannot be undone.
Laissez-le faire = Do not interfere with him.
Si faire se peut = If possible.
Cela ne fait rien = That does not matter.
Il n’en fera rien = He will do nothing of the sort.