Failing a language class can be highly stressful, particularly if you've spent all semester trying to grasp a language you just can't understand. Depending upon your school's graduation requirements, you might be required to retake the class or enroll in summer school. Failing one class won't necessarily destroy your college admissions opportunities or interfere with your college course load, but it could affect the majors and fields of study for which you are eligible.
Admissions and GPA
Your GPA is one of the most significant factors affecting whether you get into a good school. Because GPA is an average of all of your grades, however, a failed class won't necessarily destroy your application, particularly if you have high grades in other classes. If your grades are mediocre or you have failed other classes, though, a failed class could drag down your GPA and impede your ability to get into high-ranking schools. Your chosen college will still be able to see that you failed the class, but because foreign language classes are not generally core requirements, your college may be less concerned than if you had failed math or English. If, however, your chosen college places a high emphasis on foreign language competence, a failed class could lower the value of your application.
Some high schools allow students to retake failed courses the following semester or during summer school. Your school might average the two grades you receive together or replace the failed class with the grade you receive when you retake the class. This could result in a nice boost to your GPA and, depending upon your school's grade reporting policies, might eliminate the failed class from your transcript.
Some colleges, particularly high-ranking ones, require that students take a specific course load to be offered admission. If you fail a foreign language class but don't retake it, this could interfere with your ability to meet your chosen school's prerequisites. Even if the school offers you admission, you might be stuck taking remedial classes before you begin your college course work, and this can push back your graduation.
Choosing a Major
Some schools require students to obtain high grades in certain classes in order to qualify for certain majors. If you plan to be a foreign language major, a failed class could interfere with this goal. You might have to pick another major and get your grades up. Then you might be able to change majors.