* As a noun:
* The detective's telling glance at the suspect's alibi made it clear he didn't believe her.
* The artist's use of color was a telling sign of her emotional state.
* The book's ending was a telling commentary on the nature of love.
* As an adjective:
* The professor gave a telling lecture about the history of the Roman Empire.
* The children's laughter was a telling sign that they were having fun.
* He had a telling cough that hinted at his illness.
* As a verb:
* The old woman told us a story about her childhood.
* Her smile told me everything I needed to know.
* The doctor told me to rest for a few days.
The specific meaning of "telling" will depend on the context of the sentence.