When students are new to CLIL it's very important to make sure they are able to 'follow' your lesson. You can't just assume students will know certain words or certain routines. You have to keep checking in with them and pre-teach words if necessary. Some ideas:
1. Ensure students know how to articulate their needs. This means practicing non-subject-specific language: asking for help, words that have to do with sharing, working together: transactional language.
2. Implement non-linguistic ways to ask for help or ask to 'slow down'. This could be as simple as a hand signal, or using certain colour sticky notes on their desks: green= I'm okay, orange= I'm struggling/slow down, red= I'm lost.
3. Check if students understand. Not just by asking the class in general, but by making sure everybody is involved in answering the questions. This could be by using mini whiteboards, hand signals or digital apps. Keep it simple, but don't forget this step. It will save you time in the long run.