It depends on how much time you’re able to put into your studies, how often you practise using the language, and the degree to which you are immersed in it.
It is possible to acquire basic conversational fluency, i.e. the ability to understand and participate in ordinary conversations, in 6-12 months or even more quickly if you are immersed in the language and focus on speaking it. To acquire native-like fluency in a language is likely to take longer.
If your aim is to read a new language, you could learn to do so within a few months, if you are able to do plenty of regular study and practise. However acquiring the ability to read the new language as comfortably as your own will probably take quite a while longer. Learning to read Chinese or Japanese takes considerably longer than other languages as there are many more symbols to memorise.
At Elite Learning we pride ourselves on helping learners acquire the skills required for them to be proficient users of a language in the shortest possible time, thanks to our dedicated team of trainers, who provide tailor-made guidance through the whole process, whatever your motivation for learning another language.