How do you say i wish could in french?

There are a few ways to say "I wish I could" in French, depending on the context and level of formality:

Formal:

* J'aimerais pouvoir... (I would like to be able to...)

* Je souhaiterais pouvoir... (I would wish to be able to...)

Informal:

* J'aimerais bien pouvoir... (I would really like to be able to...)

* Je voudrais bien pouvoir... (I would really like to be able to...)

* J'aurais bien aimé pouvoir... (I would have really liked to be able to...) - This emphasizes that you cannot do it now.

* Si seulement je pouvais... (If only I could...)

Example:

* Formal: "J'aimerais pouvoir vous aider." (I would like to be able to help you.)

* Informal: "J'aimerais bien pouvoir venir à la fête, mais je suis occupé." (I would really like to be able to come to the party, but I'm busy.)

* Informal: "Si seulement je pouvais voyager dans le temps!" (If only I could travel in time!)

The best way to choose the right phrase depends on the specific situation and your relationship with the person you're talking to.