Full-time CELTA courses are widely described by past candidates as one of the most intensive four weeks of their professional life — expect 8+ hour days between input sessions, lesson planning, and teaching practice, often with limited time for anything else. Part-time options exist and spread the same workload over a longer period, which is easier to combine with a job but extends the intensity over more weeks. Go in having deliberately cleared your schedule; treating it as a normal part-time commitment is the most common reason candidates struggle.