Just start with the basics;that is,making a ordinary sentence and day by day take a step further. I can suggest you Essential Grammer in Use [Raymond Murphy] third edition. I believe that it will be good start for you.
Basic English Grammar by Betty Azar is excellent. It's a large red book. It is the best in my opinion.
Example about test A1 German
Quelle est la solution magic pour que je puisse communiquer en français??
How to use "bit"?
what is the difference of yet and already in making a question or when we put it at the end of the sentence?
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