If you're wondering how long it will take to learn German, you'll need to define the question a bit before you can get a good answer. Because how long it takes to learn German depends on several factors.
First, you need to find out what you mean by learning German. For most people, this means reaching a point where they have the opportunity to speak German. You can get a lot of information related to learning German via Learn German.
But for others, it could be exam preparation or acquiring highly technical written German for business reasons. Of course, the answer to how long it will take to learn German is very different for each of these scenarios.
Second, how long it takes to learn German really depends on how you learn German. There are a variety of approaches you can take, and each has its advantages and disadvantages.
You can choose a German language course. They usually take place weekly and there are more people in the class than you. This is probably the most time-consuming approach and the least recommended approach.
And there's a reason why Daily Teacher is effective. Actually, there are two reasons. The first reason is that you get a structured daily workout. The second is that the teacher will teach you to complete the sentence structure and help you understand the German sentence structure.
If you learn German with daily practice and consider sentence structure at an early stage, you have the best chance of success. In fact, you can talk in about eight weeks.