The purpose of this post is to help students have a better idea of what they can do in order to get good grades in college foreign language courses regardless of their aptitude with foreign languages. Although some of the information in this post is repeated from earlier posts, there is also new content that I believe will be helpful. Much of this content is also generalizable to other courses, and even to other levels (such as high school), but I've found that many of my own students were not familiar with these ideas, or at least the benefits of their application.
Let's start with some general things that will help with grades in any course at any level:
1. Go to class. Research has found that even if your attendance does not directly affect your grade (i.e. your grade doesn't get dinged if you skip), it will be correlated with your grade. (See for example Gunn 1993)
2. Do your homework. Research has also found that even if your homework does not directly affect your grade (i.e. the homework is not graded), it will be correlated with your grade. (See for example Cooper et al. 2006)
3. Eat right. Healthy eating habits have been shown to correlate with better grades. (See for example this report)
4. Get good sleep. Sufficient sleep has been correlated with better grades. (See for example Curcio et al. 2006)
5. Exercise. Regular physical activity has been correlated with better grades. (See for example Singh et al. 2012)
Now let's move on to college foreign language courses. Basically, this section has to do with working on the "Four Skills" beyond how you are already supposed to be practicing them:
1. Listening (you are trying to improve your ability to tell where words begin and end, and to pick out general meaning from context). I recommend that you watch your favorite movies dubbed in the language. This approach has several advantages: It's simple and easy (so you are more likely to do it). You already know the basic ideas behind what is being said (so you will understand more). You will enjoy the movies (so you will practice more).
2. Speaking (you are trying to make pronunciation, vocabulary selection, and grammar as natural as possible). The best way to practice is to simply speak in the language as much as possible in class. In the beginning this will mostly consist of you using words and phrases in the target language within sentences in your native language. For example: "Could I borrow a boligrafo?" This is great! Who cares if no one else (possibly even your instructor) is using the new language? And don't worry about perfection. This is practice we're talking about.
3. Reading (you are trying to pick out more detailed meaning than with listening). Read books that are below your regular reading level that you have already read and enjoyed in your native language (for adults I usually suggest that they pick up books that they enjoyed in their middle school / high school years). One popular approach is to read the book in both languages at the same time, switching back and forth at chapter boundaries.
4. Writing (you are trying to use the grammar and vocabulary that you are being taught). Write sentences using randomly selected grammar and vocabulary that you are covering in class. Then have someone (such as your instructor) look over your sentences and correct them. This works especially well if you provide them with a rubric (e.g. give me 5 points for using the grammar in the right way, 2 points for spelling correctly, 3 points for using vocabulary words correctly, etc.), and then having them score you and then see if you can improve your score each time.