Before you do it, though, I'd better warn you about a few things.

"I thought I'd better warn you two," the officer said.

And if so, then I'd better warn you they're running into danger.

"Although, this isn't a very good day for him, I had better warn you."

"I better warn you, nobody up at their house asked me to bring you."

But you'd better warn your people to stick to the main routes, and not to go off exploring.

I had better warn you of what will happen.

He didn't want the gang to get caught, so he'd better warn them pretty fast.

"No, you'd better warn your parents, tell them we've put our foot in it."

Thought I'd better warn you so you can be prepared.