At the entrance to Moria, he asked Gandalf the meaning of the door inscription "Speak, friend, and enter".

I would ask one thing before we go,' said Frodo, 'a thing which I often meant to ask Gandalf in Rivendell.

I should have asked Gandalf about it; and probably we should have taken more care on the road.

But if you desire clearer counsel, you should ask Gandalf.

When Frodo asked Gandalf what he thought of the monster in the water of the lake (FR p. 323) Gandalf at first replied: 'I do not know.

Ask Gandalf, if you want to know more.

Have you asked Gandalf?

As they rode south in the evening Legolas saw far off towards the Gap of Rohan a great smoke rising, and he asked Gandalf what it might be: to which Gandalf replied 'Battle and war! '

They ask Gandalf about the Trees.

(34) asked Gandalf.