Student or Learner
My phone is in/on silent mode.
Which preposition should I use?
Good question. The usage is in flux because it is so new. We normally have things in one mode or another. But if we leave off "mode", we tend to say they're on it. My phone is in silent mode, because I put my phone on silent. That "on" is trying to take over, I'd say, because we so rarely add the word "mode", and we can now say that our phone is on silent mode without sounding too weird.
What you guys think about the effect of "mode" there? Do you agree with coolfootluke?