There are 3 major points to consider in getting students to speak:
Language level of students – they must have the language required to do the task. It’s important to review language before the speaking activity.
Preparation: give students time to prepare what they are going to say; have them work in pairs or groups. Give them time to consider their ideas and language.
Reason for speaking: there has to be a real communicative element. Make sure there is a reason for speaking; practising language is not enough of a reason in the students’ eyes. Make sure there is a purpose: information gap, element of persuasion, problem solving, role play.
If you students are not communicating as well as you would like, I suggest you consider which of the areas needs more attention and work on that.
As for cheering up your students, it could just be that they are not a happy group of people. This is okay; they might still be enjoying the class. I think that as EFL teachers we want our students to have fun, play games, etc but the most important element for students is whether they are learning or not. If they’re learning they’re happy, irrespective of whether they’re playing games and having fun. Talk to your students about what they would like to study and ask their opinion of the classes; what would they like more or less of? Also ask them which topics they would like to cover in class.