If you have tried many of the suggestions in this thread, my final suggestion would be to go the route of #4's answer and look at what you are eating. I tend to believe that diet is the number one factor affecting our ability to concentrate on anything. You need to be maintaining your blood sugar, eating foods rich in vitamins and minerals, and avoiding processed, over-sugared, fried, and fatty foods.
The correlation between mental and physical health would likely be staggering to most Americans. As a society, we have some of the worst eating habits, and perpetually complain about not "feeling good."
You might want to try slowly building up the amount of time that you concentrate for. For example, if you start off with the aim of concentrating on your work for five minutes, set a timer for five minutes and then after that, if you have managed to study for that time, have a reward. Then after doing this for a few times slowly build up to ten minutes, and then gradually increase the time.
Suggestions are exactly what you need. Given that all students do not study in the same way, it would be most beneficial to try the suggestions provided and see which one, or ones, work for you. I myself have a hard time studying if it is too quiet. At the same time, I have to be in a place where I will not be interrupted. If you are studying in your room, put a sing on the door so others will not disturb your concentration.
As a warning, do not study laying down. Too easy to fall asleep if the material is not as stimulating as you would like.
You've got some great suggestions in previous posts.
Possibly the most important thing you can do, you're already doing - reaching out and asking for help because you recognize you have a problem. Good for you! Now, you need to find the motivation within yourself to take these ideas and start trying them, one at a time so you can make note of the ideas and techniques that help you and those that don't work. Different people have different ways of achieving the study environment that works best for them. You will need to experiment to find the combination of factors that is most effective for you. But the improvement in the quality of your study time will be worth it!
It helps to be doing something with the material you are trying to learn, rather than just sitting there staring at it. Try reading out loud, rewriting what you have read, acting things out.
Also, have a light snack before you start your study session. Also stop and check your diet for sources of caffeine -coffee, tea, energy drinks, iced tea, cola, and even some fruit flavored sodas contain caffeine, and consuming it make make your jittery and unable to stay focused.
Sometimes we have to build up to this in baby steps. As you study, you might want to try to work for about 15 minutes at a time, take a break for a while, and then go back to studying for another 15 minutes. During that 15 minutes, be somewhere you will have no distractions. Don't text, talk on your phone, or do anything but focus on what you need to work on. Once you can do that successfully for a short period of time, you can build up in gradual increments.
One way to achieve better concentration may be to study with another person. Discussing your studies with someone else can help better embed crucial information in your memory. If you are having trouble concentrating in all your subjects, let the school guidance counselor know this. S/he may have some good suggestions for you. Good luck!
Sometimes it is hard to concentrate on something because you can get distracted by something else. You can study with a friend or a group of your friends to keep away the boredom. Or you can turn off all electronics and put away the things that distract you so you can finally concentrate on work.
Concentration can sometimes be easily won but also easily lost. The best way to gain your concentration back is to do what ever is taking your concentration away but give it a time limit. Sometimes I will loose my concentration while studying if I had read a chapter of a book before and I can not take my mind off of the book. If it gets to the point where I am not even studying anymore but fantasizing I just cave and read for another 30 minutes or so to relive my head and before I know it I am able to concentrate.
Set a set schedule for when you will study and make sure you keep all distractions away. Instead of later, start now and simply do it and work hard, pay attention to what the result will bring.
log out of facebook and start your homework, yep.