https://mikeastbury.wordpress.com/2016/02/17/agree-or-disagree-and-why/
Scaffolding discussions for quiet students
Some of my new classes this term have students who either whisper, speak in L1 or stay completely silent during speaking activities (even at int/upper int level). Part of this reluctance to speak seems to stem from having no knowledge or strong opinions about the topics being discussed, or not having enough time to think about an answer before a more confident student dominates the conversation.
This activity was designed for quiet and shy students by helping them start from expressing a single opinion to engaging fully in a debate.
English The Right Method 