Do you need a teacher to learn a language?

Lately I have been wondering if language is learnt more effectively with or without a teacher (meaning any person having a good command of the language, with or without an actual teaching degree). I have mixed experience on this subject, and I will share my experience of learning French and German.

I have learnt German entirely on my own since I was 14, by using some coursebooks at the beginning and reading many authentic materials later. At the moment I am fairly fluent in it, and I have never felt that it would have been better had I taken a course of it. For a long time I had some difficulty speaking in German though, simply because I wasn't used to it. On the other hand, I started learning French at high school, and having the teacher as a model helped me master speech patterns faster. Now with a fairly good command of both languages, I think I could learn any Germanic or Romance language easily on my own, without a teacher.

However, if I decided to learn a language pertaining to a different culture (such as Chinese or Hindi or Arabic), I feel I would need somebody to serve as a model for pronunciation, at least in the beginning, and to make me aware of the sociolinguistic aspects of different expressions (e.g. it is all right to use an expression in one situation, but would be more than inappropriate in another). In other words, to master the language of a different culture, I would need contact with a representative of that culture. I would appreciate any coments on this subject.

The teacher is needed for inspiration and motivation where that is lacking, for feedback from time to time, especially in correcting writing, and to provide a native speaker to talk to where that is otherwise lacking. A teacher can also help when one gets stuck in a text and cannot understand despite having all the words. More than anything a good teacher can keep the learner going and accelerate the learning praocess.

Pronunciation is best learned from constant listening and imitating and comparing one's one recorded voice with the native speaker.

Having learned Japanese, Chinese and now Korean I can say that the sociolinguistics of the language are most easily learned by observing and gradually learning to imitate from a great deal of input in the form of constant listening and reading of authentic content. As with many aspects of language learning, teachers explanations would be ineffecive until the learner has had enough input to sense how varying forms of politness are used.By that time explanations are often superfluous.

I learned French on my own, by reading books, listening to cassettes and CDs, and trying to write. It worked very well. I did try taking French classes briefly in school, but they were so abysmal and so useless compared to what I had already learned on my own that they don't really count—I never learned anything from any of the French classes I took, aside from one single 40-minute period during which a substitute teacher with a very good knowledge of French provided some interesting pointers on pronunciation. But even that pretty much pales compared to all the study I did on my own.

So you can learn without a teacher, if you are very motivated. I think you do need some audio examples at some point, though; I'm not sure if one could learn good pronunciation without any speech samples at all, but if one can, it must be very difficult.

You can also learn a language by imitation, trial, and error, as small children do. But remember that it takes children a decade or more to master a language that way, and that's with nearly full-time study, so you might be looking at a long, long road to fluency.

hard to say. I guess you can do it either way. I learnt spanish for three years in college and it went quite well but i also learnt russian by myself. I didn't really find it very hard to learn it either way only I had a little more problems with pronunciation when learning by myself but nothing that i couldn't fix when watching videos and listening to tapes. Also i learned a lot faster by myself because the pace in school was incredibly slow.