When do you use je peux and when do you use je puis?

Answer 1

'Je peux' is the present form for I can, I am able to, I may. This is the simplest and most useful form. 'Je puis' isn't used any more; it is an outdated writing of Je peux. Nowadays you should use 'je peux' and avoid 'je puis'.

Answer 2

"Je peux" is used more commonly in everyday conversation to express "I can," whereas "je puis" is a more formal and literary term used to express the same meaning. It is rare to hear "je puis" in modern spoken French.