Mahoney recommends that scripts should not be too explicit.

'Drama shouldn't tell too much too quickly. It shouldn't tell you directly, otherwise it gets boring and you'll lose tension in the script.'

Mahoney told students that their characters' emotions should show through 'without spelling them out'.

Contrasting characters with each other is another way to make the script interesting to listen to.

'In radio drama, we don't have visual elements - everything is in the language,' Mahoney said.

'If the characters are too similar, it's difficult to distinguish between them.'

To make the dialogue sound more natural, informal language should be used instead of written language.

'Spoken language is messy. It is not like written language, which is neat.'

When developing the story line, Mahoney suggests tension and conflict should be added to attract listeners' attention.

In addition, Mahoney said adding a bit of humour, such as playing with words in the dialogue, would make the story more absorbing.

Samuel Yau Kwan-shun, 15, from La Salle College, who has been a radio actor for nearly two years, thinks a good story should not be too far-fetched.

He said: 'You should write something that is close to reality, something that people can understand and relate to.'

From an actor's point of view, he said a synopsis of the plot helped him handle stories more easily.

Another radio actor, Jessica Chan Tin-wai, 20, said when working on a story in a group, it was better for just one person to be responsible for writing the script. This way, the storyline would be more coherent.

Winning scripts will be broadcast on RTHK Radio 4 next year on the Songbirds show.

The deadline for the Songbirds Radio Drama Writing Competition is next Wednesday.