be a dead giveaway

It was a dead giveaway to where Patty would be going.

It's a dead giveaway that they are up to something.

But the ones who start off nasty, they say, are dead giveaways.

If anyone looks in, it's a dead giveaway of what we are.

To turn back toward his house would be a dead giveaway.

But right on top, in plain view, the skull was a dead giveaway.

Back in the early days, the arrow through the head was a dead giveaway.

But for the knowing eye, there is a dead giveaway.

Sam hasn't the mobility or the control she should have, and the child is a dead giveaway.

The walking stick in her right hand was a dead giveaway.