If you are learning a language merely for self enrichment, it is always possible. Resources are available over the internet and all you need is to "google" them out. It is also possible to attain proficiency in text-chatting, writing letter/email, listening etc through self learning. If your intention of learning a language is to communicate verbally with someone ultimately (of course self-learning helps when building up the basic), you will need to practise it with someone, eventually. By practising the new language with a "live" partner, it enhances your ability to encode and decode the messages in that language. The process trains you to stay attentive as you wouldnt know what sentences your "live" partner is going to say next. It also allows you to form sentences on the fly in order to express what you want to say. Just my two cents' worth.

Hello Naij, It is possible but it will need more time and effort and it will be more monotonous and surely you need to practice with others specially natives .If you could substitute online language environments with any other real language cultural environment it would be possible. But just book and tape without applying it , I don't think it will be very effective .You might be able to write and read but when speaking with others you will find that your speaking and listening skills were not developed the same . So probably the combination of self learning and auxilary language environments will help you develop the different skills you need to master the language.

No...because it will need a correction pronounciation in every single word. Just like in my case I have hard time in studying chinese mandarin although their is an instructor...

i have learnt many languages by myself but i am only able to read those languages, when comes to speak i am null. one way, but take a lot of effort, is listening to radio until you get familiar with the sounds and later with the words. it takes a lot of time and you have to listen constantly and passively, that to say, put on the radio and let it sound even if you don't understand nothing, day after day. when you start to get the words repeat them to you, then repeat phrases and so on. of course keep on with the books and grammars too.

Yes one tip though if you are learning a language by yourself is to understand that languages grammar points and its grammar terminology (in your native language and the language you are studying). for example in chinese they have complement of potentiality, or complement of results. also study and understand the meanings of basic grammar terms like: pronoun, adjective, adverb, noun etc. so when you open a language learning book it makes the information clear.