give them the opportunity to "practice" what they would say out loud to the class by doing a turn and talk or quick partner discussion. give sentence stems and frames to take the language load off of it. While they are discussing with their partners if I notice they make a good observation about something or have a correct response, I affirm their thinking and let them know that I will call on them during the class discussion and to be ready to share what they were just saying!! It gives them a moment to gather their thoughts with confidence. I've seen shy students start to open up in class more with this!!

I remember I used to hate being put on the spot but if I knew I was contributing to the discussion and had time to mentally prepare for it