To pass, or not to pass.

Should they stay or should they go...
I am torn over the kids we are teaching in summer school. I want to help them all, but that is impossible, especially since some of them don't want help. Around a fourth of the kids seem to have real difficulty mastering the concepts we discuss. The other three-fourths are just lazy--they failed during the school year because they had too many absences or they did not do any of their homework assignments. The lazy kids I have little sympathy for, but the kids that try very hard but just can't seem to get it are the ones that really tug at my heartstrings. It is hard for me to identify with them, so I am not really sure how to relate to them. It has become obvious that repeating the material over and over does not work. I have tried explaining the objectives from as many different angles as I can but I am still not reaching everyone. When asked to identify the verb in a given sentence the kids will guess every single word (if you let them) rather than thinking about the question and analyzing the sentence. Today I had to grade their persuasive writing papers. It was possibly the most frustrating experience of my life. It actually gave me a headache. You know it's bad when you have more writing on a student's paper than they do! The kids knew this assignment, which they have been working on for two class periods (and are supposed to be working on at home) is worth the same as a test grade, yet only a little over half of them turned in the assignment today. It just seems like they don’t care! It will be interesting to see how many of them end up passing. I am pretty sure the teacher I am working with will pass more of them than she should. Apparently, a lot of their previous teachers passed them on when they really shouldn’t have. However, if a kid fails does that not mean that I have failed that kid in some way? I do not want to fail any of my kids (both meanings of fail as used in the previous sentence) but what do I do when they just don’t care. How can I make them care? Or even worse how can I tell when they are just pretending to care but then they don’t put any thought into their assignments or don’t do their homework.