When does Navi to talk to me?

Hit up C and she will talk to you when she has something to say. I think she has something to say in the following situations:

• you are locked on to an object/enemy
• asks you to listen to her. (The super annoying Hey listen!)
• she flies away and hovers over an object.
• a picture of navi appears next in your HUD by the c button controls

You can also play saria's song and decline to talk to saria. Navi then asks you if you want to talk to her.

Her "Hey, listen!" triggers simply come up every so often to make sure you're not lost. Pressing C-up to speak to her then will give you a general hint about where to go or what to do next.

If you'd like the hint on-demand, you'll need to play Saria's Song and decline when asked if you'd like to speak to Saria. You'll then be given the option to speak to Navi.

You can also speak to her via C-up when targeting an enemy in order to get information about that enemy as well as hints to fighting it.