A girl's obession

I know there are a lot of grammar errors in this but never took the time to correct it. I just want to show you this story...

Walking down the train tracks, on a cool fall day three years ago on my way home from high school. I saw a girl slowly walking down the same path I was. I walked up to her just to say hello, since I was in a friendly mood that day. The girl has to be around 15 to 16 years old, baby blue eyes and short red hair. When she said "hi" back in reply she had a smile on her face, likely she was thinking about something before I came to her. Her name was Kasey, with a 'k'. She lives only a few blocks from where I live. Not also did her path home crossed with mine but she went to the same high school as me.
While walking we were talking about school, our friends and family, and mostly just small talk. However she talked a lot about her boyfriend. Saying that she couldn't wait to meet him when she gets home. How they both met and fell in love, what they have done and their plans to do in the future. She even showed me a picture of them together. I thought to myself that these two make a cute couple. Kasey and I came our separate ways when she came to her house. Later that evening at home I talked to a good friend on the phone. I was telling him about Kasey and her constant talk about her boyfriend. My friend knew who Kasey was and told me that her boyfriend that she's obsessed with has been dead for almost three months now. He had a sudden illness and was taken to hospital where he stayed for a week and died not soon after. Kasey was so devastated that she wasn't the same afterwards. She barely slept, eaten or talked to anyone for a couple of weeks, and then she started acting or pretending as if he was still alive. Everyone around her tried to talk her out of it from friends to family, but she never listened.
The next day, after school on my way home I ran into Kasey. I told her, "You know your boyfriend's passed away for some time right?" She replied laughing, "What are you talking about?" I told her about his illness, she said he almost came close to death but survived. Whatever I would tell the girl about her lover's death and convinced her that he was dead, she would deny it in some way. Kasey was eventually upset of me talking about his death and said I was a bold-faced liar. For the rest of the walk she ignored me and didn't talk to me ever since. I found out from my friend that her and her family's moving out of state. Maybe it's just their way of getting Kasey to let go of the past. Three years have past by and I still wondered and hope for her sake she moved on. Last week I got a call from my friend said that she has a new boyfriend. The weird thing about it is she keeps calling him by the same name of her dead ex. My friend e-mailed me a picture of them and the guy even looks like a spitting image of him. I bet she still thinks it's the same guy. Since then, I still worry about that poor girl...

It gives a good basis for a psychologically based storyline.   It's not my kind of theme, but I know a lot of people enjoy it.  

It might just be the forums squashing it, but I think splitting it into more paragraphs would make it easier to read.

It provides an interesting basis, but it's crippled by brevity and quick scene changes. Ultimately, I'd like to see this fleshed out more into a full-fledged short story, and think that with the right touches and flourish, could amount to a quite interesting read.

It feels too much like a movie trailer instead of an actual movie. You know what I mean? We don't really get to know the characters, we just get the general gist of the overall goings on. There's a girl and her boyfriend died, and she hasn't accepted it yet. There's nothing more to it than that, really.

However, there are a few glimmers at being able to build some stronger characters in there. The line about Kasey, "with a K," made me smile, as it did shine a little light on her character, but unfortunately was the only such development. With some more embellishment in that regard, it'd definitely help to hook the reader more thoroughly.

You should also keep an eye on your verb tenses. Outside of the grammatical problems, which you already pointed out are there, this is probably one of the lesser visible things, and takes a little practice for a writer to keep a keen eye on ensuring that everything stays within the confines of a specific tense. You tended to switch a lot between past and present tense in the first paragraph, and that should bear some attention.

Still, an interesting premise, and again, I'd like to see you put some more time and effort into it. I think it could be a solid body of work, but for now, it's still a work in progress.

So if you go back and revise it, please put up the new version(s) too! :D

I agree with Ether, it definitely needs to be fleshed out further to work well as a story.

I think I may have to steal a part of the premise for a campaign that I'm going to be running in the near future (now that university is wrapping up)...  It should provide for an interesting adventure hook.  You don't mind do you?