Similar experience, 17,400 words. German, speaking English on a daily basis, had 8 years of English in school and 9 years of Latin, which probably helped me a

Similar experience, 17,400 words. German, speaking English on a daily basis, had 8 years of English in school and 9 years of Latin, which probably helped me a bit. (Though I hope my teachers don't read this) Does anyone know a similar test for grammatical proficiency?