spend use cost
If they use the language only 2 or 3 times a week,learning it will [MASK] a long time,like language learning at school.A few people try to learn a language fast by studying for 6 or more hours a day.It's much easier to learn the language in the country where it is spoken .But most people are unable to do this,and many people don't have to do so.Machines and good books will be very helpful ,but they can not do the students'work.