The Communication Trust supports speech, language and communication in England and, if you register, you can access their database of what works.
They also have downloadable resources that can be used to support the development of talk.
Shakespeareandmore.com is a great site which has lots of ideas for developing whole class, group and paired discussions.
One of their ideas is to hold a ‘no pens day’ during the school year – or more than one. This is a day when no writing takes place; instead all learning happens through the medium of talking and listening. You could make a human graph in maths, or use video clips or debates to support learning. A supporting activity pack can be found here: no pens day supporting resources
Supporting talking in the classroom
Education Scotland’s Language of discussion stems can be used to teach children the language they should use in discussion situation.
Talking round corners is an approach to teaching talking and listening that can be used: for further information and a sample lesson plan, visit https://highlandliteracy.com/2015/03/09/talking-round-corners/