Should I apply with a non-subject LoR to a university? I am applying for a master’s program in computer science. I am using two letters of recommendation from the computer science field and one LoR from the language department where I learned a foreign language. Although the foreign language was part of my undergraduate education, does using a non-department LoR create a problem for graduate admissions?
Your recommenders should be able to vouch for your previous performance in undergrad and explain why you would be successful in a graduate program. A foreign language instructor might be able to provide the first part, but they might have more trouble with the second.
If you believe that your foreign language instructor could write you a strong letter highlighting characteristics that would make you successful in your program, then they might be a good person to ask. It will not necessarily harm your application to have a letter from such a person, but a letter from someone in your area might be stronger.