How will an F from study abroad affect my chances at a top grad?
Most likely a top grad school will not like it but I dont think it is a deal breaker. My son earned 1 F out of 50+ undergrad classes and still was accepted into a selective masters level program with a graduate assistance. One key is how you explain the grade. Do not try to hide it or make excuses. Be open and upfront. If it is an embarrassment, state so and state it is your motivation to insure that it never happens again. If, by some chance, you are denied entry to a top grad school, remember that are many fine schools available. An advanced degree carries a lot of prestige no matter the institution you earned it.