They both listened alertly, unable to see anything yet.

Vincent listened alertly; he heard only a single word: "Look!"

He was listening alertly, eyes fixed on her face.

Listening alertly is trying to understand what people are saying rather than just hearing the sounds that someone makes.

He described the boy as the teaching machine listened alertly.

Just like that ancient advertising logo, the dog listening alertly to the radio or whatever it was.

Inside, he deposited Della on the floor and sat just within the opening, alertly listening for suspicious sounds.

Crofts listened alertly to the sounds of a vessel preparing to slip.

He sprang from the boat listening alertly for any indication that his approach had been observed.

As he caught the sound of my steps he stopped, listening alertly.