Peer observation is a core, graded CELTA activity — you’ll regularly watch fellow candidates teach and complete observation tasks. Focus on specific, describable behaviors rather than vague impressions: not “the lesson felt engaging” but “the teacher used a personalized example in the lead-in, and most students volunteered answers within the first two minutes.” Concrete observation notes are both more useful to the person you’re observing and better training for your own self-reflection.