Here is the conclusion of a report from Australia that I found on another forum.
Canberra TAFE ‘forecast 1756 hours of teaching to get from no English to to the level of competence required for further study or a job.’ (p46)
The author then breaks down these hours into possible projections:
full time 16-19yr old students @450 hrs a yr – 4years;
adult students @10 hrs a week @300 hrs a yr – 5yrs 7mnths;
adults attending 4hrs a week @ 120 hrs a yr – 14yrs 6mnths.
It is interesting that teachers always assume that teaching is the key to learning, and the classroom is the only place to learn. In my view the learner is the key to learning, and the classroom is only one place where learning can take place, and not the most effective place.