Why tutoring is faster an cheaper than German classes at a language school
1) Not Conversational
Franky speaking, you only learn a language by practicing and using it. If you spend 60 min at a class room - even with only 5 students - the time you will engage in a conversation by using German is about 5 min max. A good tutoring session will engage you in a one-to-one conversation at least 80 to 90 percent. This means you don't get only twice as much, or three times as much, but 10 times more time to practice German.
In other words: You need to sit down in a class room for 10 hours to keep up the same learning speed you get in a 60 min one-to-one tutoring lesson. This is one of the main advantages of private lessons if it comes to learning a foreign language.
2) Class Mates as Role-Models
Even you get the chance to speak German during your course, you will mostly talk to other students in your class room. This might be good for finding new friends and play funny games but it has one big disadvantage: You will simply copy the same mistakes and all the wrong grammar from your class mates.
On top of this, none of your class mates will be able to correct you. Instead you will be exposed to wrong sentence structure, to wrongly conjugated verbs, and wrong grammar most of the time. And you will reproduce these mistakes and internalize them from the very start. So why would you ever pay for a setting in which other students are trying to teach you their own limited German? This is not learning from the best but learning from those who do not know it better than you.
3) German Textbooks
The open secret most teacher would agree on is: Text books used in schools are not made for learning German. They are designed to serve the demands of the teacher. Why? Because the class has to function, meaning your German teacher has to keep all students busy for the whole class. And keeping all students busy is the main purpose of the teaching methodology. Therefore, the exercises you find in a typical German textbook will serve the teacher, his occupation, and his role of setting up a functioning group dynamic first. Only after that, textbooks address the needs of the students to actual learn a language.
The second reason why these textbooks don't work is because they are based on the wrong methodology. The core of this methodology, no matter what they claim, is a test-methodology. The teacher needs to be able to test and to score your capabilities. Therefore, most textbooks I have seen are based on a simple testing-methodology which is also used for exam: You fill out gaps, solve puzzles, and create answers which can be easily checked by the teacher. This is good for the teacher but bad for you because testing your capabilities does not support you in learning German at all.
The third reason why textbooks usually are terrible for learning a language is that their content is not contextualized. Did you wonder why it takes you so long to understand even a simple exercises in your German textbook? It's because they are badly designed. Even a German native speaker usually needs more time to figure out what these exercises are all about than to actually solve the puzzle and fill out the gaps. And neither solving the puzzle nor trying to understand the purpose and the structure of the exercise will help you to learn German.
Thus, the methodology developed for testing and certifying the students German, but also for supporting the teachers needs to engage the students with little assignments, is misused for actually teaching a language. That is the reason why you almost have no chance to engage in the language while running these exercises. They are not made for learning but for simply checking and quantifying your answers and for providing the teacher with enough little puzzles so the students will stay busy.
4) No Bilingual Classes
If you take a German class at Goethe Institut, for example, they will teach you "German in German" from the very first lesson. This "immersive" approach sounds promising but it is extremely useless at a A1 or even at a A2 level. This procedure was mainly developed because there were simply not enough German teacher available who could speak the native language of their students (mixed classes). Until now the concept of using exluseivly German from the very first lesson is still the standard procedure in Germany. If you ask why, the teacher will sell it to you as a proper methodology, while it's actually an outdated strategy to overcome economic limitations.
Consequences: As a result you will spend 80 percent of your time for translating vocabulary by using dictionaries. This is frustrating, slow, and not efficient at all because you learn nothing. You also will be confronted with exercises you don't understand. Most of the time needed for your homework will be used up by trying to understand what the textbook actually wants you to do.
Solution: Today most students speak English as a second language. This makes it easy to use English as a working language to explain grammar and to develop bilingual worksheets and exercises. I would estimate that with bilingual exercises & lessons your learning speed is at least 4 to 6 times higher compare to a standard monolingual class room lesson at a language school.
5) Wrong Speed
Finding the right pace in a group lesson with 5 or even 10 students is almost impossible. Usually the German teacher will try to compromise between the most advanced students and the ones falling behind. As a result, at least half the students will be bored or frustrated. In other words, language classes at a school are more or less useless for half the students, and are very inefficient for most of the teaching-time students are paying for.
A tutor on the other hand will automatically adjust the pace to the students demands. To be able to slow down is one of biggest advantages of tutoring. Spending another round to work on something you are not able to comprehend or to use will, at the end, speed up the entire learning process dramatically. For me personally, not being able to adjust the pace is one of the most frustrating issues when I teach group lessons in a class room.