Is "impinge" used correctly in this sentence:

Studying Latin every day impinged her grades in both Latin and English.

No.

Please study this definition carefully and try again.

http://www.merriam-webster.com/dictionary/impinge

Yes, the word "impinge" is used correctly in this sentence. "Impinge" in this context means to have a negative impact or to encroach upon something. In the sentence, it suggests that studying Latin every day had a negative effect on her grades in both Latin and English.