Do you want to have proof over your ability of speaking German? Take an exam. There are different exams out there with which you can proove your language ability in different skills, like listening, reading, speaking and writing. Some of them test Grammar as well.
Here are a few examples of the most common and widely accepted language exams you can take:
In Germany all language abillity is referred to the GER, (Gemeinsamer Europäischer Referenzrahmen für Sprachen), the European Framework of Reference for Languages. Check out the information here: Gemeinsamer Europäischer Referenzrahmen (GER) für Sprachen (europaeischer-referenzrahmen.de)
Level A: Elementare Sprachverwendung (elementary language use)
Level B: Selbständige Sprachverwendung (Independant usage of language)
Level C: Kompetente Sprachverwendung (competent usage of language
TestDaF:
an exam which is addressing to students who plan to study in Germany. You can take the TestDaF already in your home country and if you achieve a high enough level, usually a TDN 4 or 5, you can immediately inscribe to study at a German university if you fulfill all the other requirements. If you can’t show a proof of your ability in communicating in German, you won’t get admitted to a German university. You will get 3 different texts, one more difficult than the previous one, to test if you are TDN 3, 4 or 5. Same for the listening skills. You will listen to 3 different listening texts, one more difficult than the previous one. They test your listening ability on level TDN 3, 4 or 5. The speaking section is usually taken place via a computer. You will listen be on a computer with a headset and listen to some speaking prompts to which you react. Later a teacher will listen to your answers and will grade whether your speaking ability is TDN 3,4,or 5. To test your writing skills you will get writing prompt in which you always have to analyze a chart or table and later discuss a problem based on that statistic. A teacher later will read your text and grade it whether you are on level TDN 3, 4 or 5 on your writing skill.
Check out their homepage: Test Deutsch als Fremdsprache (testdaf.de)
Goethe-Zertifikat:
The Goethe-Institutes around the world offer exams on all 3 levels, A,B, and C. These certificates are widely accepted in companies and other facilities where you have to show a proof of your ability in communicating in German. In their tests on each level they test your listening skills, your reading, speaking and writing skills. They offer an exam for professionals as well.
Look at their homepage: Unsere Deutschprüfungen – Goethe-Institut
Die Deutsche Sprachprüfung für den Hochschulzugang:
The German Universities offer their own language tests as well. You have to apply for them directly at the university. For the DSH you will read a text and answer questions to it. The same is for the listening part of the exam. Differently to other exams you will have to work on a part of scientific structures. This will ask about the German Grammar. You will need to recognize some grammar forms and transform them, z.B. Nominale Phrasen in verbale Phrasen, why the Konjunktiv II is used in this context or similar questions. Then you will have to write an essay in which you will have to explain, compare or comment on a specific topic. For the oral exam you will get a short text or a chart or table. You will get 20 minutes of preparation time and during the exam the tester will ask you about that text or will have question further on or will ask you to give your opinion toward that general topic.
Get more information about the DSH: DSH I Deutsche Sprachprüfung für den Hochschulzugang
Defense Language Proficiency Test (DLPT)
The Defense Language Proficiency Test will test your reading and listening skills. You will get several texts, each more difficult than the previous one to see when you are not able any more to answer the questions. This will indicate the level of proficiency you have right now.
Check the DLPT: Defense Language Proficiency Test (DLPT) (veteran.com)
Oral Proficiency Interview OPI:
At the OPI you will talk to a language tester on the phone. You will have some warm-up questions which often lead to more in-depth questions for you to answer. The questions will become more and more difficult to test how well you can express yourself on different proficiency levels. At the end there will be wind-down questions. The OPI doesn’t ask about how you aquired the language or with which method you have learned. Neither does it judge your opinion to a certain topic. It just scores how well you master the language.
Read more about the OPI here: Oral Proficiency Interview (OPI) – Online Language Test (languagetesting.com)