"I work long hours and don't have much time to travel to language schools. Private one to one lessons at my office are ideal as sessions can be planned around my work schedule. I have been studying Japanese with Noriyuki for over 2 years and making good progress! These lessons have made my trips to Japan more enjoyable and interesting."
Around half of the students which I teach in this manner are complete beginners whilst the other half have previous experience of learning in a formal classroom situation but did not continue as either they found the course unsuitable or that the timings were inconvenient for them. By arranging to be taught in your home or in your workplace, you can fit your learning into your life as opposed to arranging your life to suit your learning.
Learning in a group can have some advantages as you will be able to practice with your co-students - helping and learning from others can stimulate your learning and make it more interesting. Either you can form your own small group e.g. with friends or partners or I may be teaching other students of similar levels which would be interested in joining you. There are naturally cost advantages to be considered as well.