Final answer:
The sentence contains a capitalization error where the word 'german' should be capitalized, as it refers to the language or nationality in the corrected sentence.
Step-by-step explanation:
The sentence 'Since I made such high grades in Chemistry and german, I enrolled at the local junior college.' contains an error concerning capitalization. The word 'german' should be capitalized as it is a proper noun, referring to the language or nationality. The corrected sentence should read, 'Since I made such high grades in Chemistry and German, I enrolled at the local junior college.'