Because I was afraid that I could'n't fininsh my 2 km- running alone, I needed someone to guide me. Because I was afraid that I couldn't finish my 2 km run alone, I needed someone to guide me.

could not -> couldnot -> couldn't

Because I was afraid that I could'n't fininsh my 2km- running alone, I needed someone to guide me. Because I was afraid I couldn't finish my 2km run alone, I needed someone to guide me.

Because I was afraid that I could'nt fininsh my 2km-running alone, Iand needed someone to guide me. I was afraid that I could't finish my 2km-running alone, and needed someone to guide me.

Marathon running was popular a few years ago, especially among the white collars and the enterprise workers and entrepeneurs. Marathon running was popular a few years ago, especially among white collar workers and entrepeneurs.

Or "Marathons were". Singular "marathon" almost always refers to a single marathon event. He ran a marathon yesterday. They will be having a marathon in town next weekend.

MRunning marathons was popular a few years ago, especially among the white collars and the enterpriseworks and entrepreneurs. Running marathons was popular a few years ago, especially among white collars works and entrepreneurs.

Marathoning was popular a few years ago, especially among the white collars and the enterprise workers and entrepreneurs. Marathoning was popular a few years ago, especially among white collar workers and entrepreneurs.

I sighned up a game for a 5 km- running competition once, but I was too busy to attend. I signed up for a 5 km running competition once, but I was too busy to attend.

I sighned up a game for a 5km- running once, but unfortunately I was too busy to attend. I signed up for a 5km run once, but unfortunately I was too busy to attend.

I sighed up a game for a 5km-running race once, but I was too busy to attendgo. I sighed up for a 5km race once, but I was too busy to go.

Attend is usually used for classes.

Recently, I am reading an erotic article. Recently, I am reading an erotic article.

Grammatically this is fine, but I'm not sure if "erotic" is really what you want? This means that you're reading a very sexual article, an article intended to make the reader sexually excited. If that is what you mean, in English we'd probably call it a "romance novel" or a "romantic serial", something like that - we're shy :)

Recently, I am've been reading an erotic article. Recently, I've been reading an erotic article.

Recently, I am reading an erotic an article. Recently, I read an article.

I don’t know what you are trying to say here. Erotic means explicitly/graphically sexual.

The manle actor runs every day, so he is in good body shape. The male actor runs every day, so he is in good body shape.

"man actor" is okay but sounds a bit awkward.

The main actor runs everyday, so he is in good body shape. The main actor runs everyday, so he is in good shape.

The man actor runs everyday, so he is in good body shape. The man actor runs everyday, so he is in good shape.

And there is a girl who always goes running, she looks good, too. And there is a girl who always goes running, she looks good, too.

And tThere is also a girl who always goes running, s. She looks good, too. There is also a girl who always goes running. She looks good too.

And there is a girl always goes running, sone girl runs also. She looks good, too. And one girl runs also. She looks good, too.

I know there are many advantages of running, but I don't like it, but. Although I don't hate it either. I know there are many advantages of running, but I don't like it. Although I don't hate it either.

"although" is just another way of saying "but" so that you don't have to repeat yourself. You needed a conjunction between the first two ideas, they contrast too much to simply use a comma.

I know there are many advantages tof running,. I don't like it, but I don't hate it either. I know there are many advantages to running. I don't like it, but I don't hate it either.

I ran occasionally in recent years. I ran occasionally in recent years.

More natural: "I've run occasionally in the past few years."

I ran occasionally in recent years. I ran occasionally in recent years.

In recent years I ran occasionally recent years. In recent years I ran occasionally.

But I like swimming most. But I like swimming most.

I like swimming mostre. I like swimming more.

You could also say “I like swimming the most”

Since I live in a small town without a swimming pool, and it's too inconvenient to go to the pool, so II've decided to run again. Since I live in a small town without a swimming pool, and it's too inconvenient to go to the pool, I've decided to run again.

"Since" and "so" were both doing the same thing - each of them is in the correct place for the correct reason, but you only need one of them. Simple present tense isn't good here. You could've used simple past "I decided", but present perfect "I have decided" is most natural, because it's a past decision with present consequences. In the past, you decided, but because of that past decision, you are presently in a routine of going running.

Since I live in a small town without a swimming pool, and it's too inconvenient to go to the pool, so II have decided to runtry running again. Since I live in a small town without a swimming pool, and it's too inconvenient to go to the pool, I have decided to try running again.

Since I live in a small town without a swimming pool, and it's too inconvenient to go to the pool, so I decided to run again. Since I live in a small town without a swimming pool and it's too inconvenient to go to the pool, I decided to run again.

OncThere was one time I ran 3 km at least. There was one time I ran 3 km at least.

Once I ran 3 km at least 3 km. Once I ran at least 3 km.

But I hadn'rt run for a long time, even 2 km was even a little hard for me. But I hadn't run for a long time, even 2 km was a little hard for me.

It sounds better this way round, but I'm not sure exactly why.

But I hadn'rt ruan for a long time, so even 2 km was even a little hard for me. But I hadn't ran for a long time, so even 2 km was a little hard for me.

But I hadn'r t run for a long time, so even 2 km was even a little hard for me. But I hadn' t run for a long time, so even 2 km was a little hard for me.

I asked a friend, who loves running and is wild about marathons, to run with me. I asked a friend, who loves running and is wild about marathons, to run with me.

This would actually work without any commas at all, but once you started off the parenthetic clause with the first comma, you needed another comma to finish it before continuing the sentence.

I asked a friend, who loves running and is wild about convincing me to run a marathon to run with meher. I asked a friend, who loves running and is wild about convincing me to run a marathon with her.

I asked a friend, who loves running and is wild about running marathons to run with me. I asked a friend, who loves running and is wild about running marathons to run with me.

From then on, I never registered any more. From then on, I never registered any more.

More natural: "I never registered again".

From then on, I never registerded for another run any more. From then on, I never registered for another run any more.

From then on, I never registered any moregain. From then on, I never registered again.

There was also a book popular inat the same time, which was written by the Japanese author Murakami Haruki. There was also a book popular at the same time, which was written by the Japanese author Murakami Haruki.

The English convention is to say Haruki Murakami. Of course this isn't wrong, but just to note :) "in" is okay but "at" sounds much better here.

There was also a book popular during the same time, which was written by the Japanese author Murakami Haruki. There was also a book popular during the same time, which was written by the Japanese author Murakami Haruki.

There was also a book popular inat the same time, which was written by the Japanese author Murakami Haruki. There was also a book popular at the same time, which was written by the Japanese author Murakami Haruki.

Its name is " What am I tI Am Thinking aAbout wWhen I aAm rRunning". Its name is "What I Am Thinking About When I Am Running".

Convention is to capitalise the first letter of each word in a book title. "What am I thinking about" is the word order for asking questions. This may just be a quirk of translation, but English sources give the title as "What I Talk About When I Talk About Running" :)

ItsThe name is " What am I thinking about when I am running". The name is " What am I thinking about when I am running".

I haven't finished reading the book for a long time. I haven't read the book for a long time.

"I haven't finished reading it" is what you would say if you *are currently* reading it, but you have not finished yet. Or if you gave up, and never finished.

I haven't finished reading the book again for a long time. I haven't read the book again for a long time.

I haven't finished reading the book forin a long time. I haven't read the book in a long time.

Well, I was thinking about "what I am I thinking about when I am running." Well, I was thinking about "what I am thinking about when I am running."

You should probably do title capitalisation here too, but I'd say it's up to you :)