Good communication – and good teaching – is about understanding and being understood. For this reason, you should always be clear and unambiguous, and adapt your words to your audience.
Think about this while writing lesson plans, but also while you interact with the children after presenting the lesson. For example, you may wish to check that your teaching was clear by asking your students/participants questions, or requesting summaries of the lesson in their own words.
When you ask your students/participants questions, use appropriate scaffolding to ensure that they understand exactly what you are asking.