And if you don't have a "partner" or any similar person within talking range (in person spreads more energy for creativity than talking on the phone or in a text chat), you can talk to yourself or imagine someone else listening.

I have several personae (SIC--a latinate plural for words that end with the "feminine" "-a") with whom I chat depending on the content and context. The beauty of it is that I can verbally "slug" the negative Nileses and Nancies, and shoo them away--while rewarding with big smiles those who offer support or constructive criticism.

I've also been known to have written dialogues with people, including those who, like the poet William Blake, died a long time ago. It's a great way to get new ideas when you're stuck.

Alas, my writing partners are rather loquacious.