Today I runan a distance of 20 km Today I ran a distance of 20 km

Today I ruan 20 km Today I ran 20 km

Past tense: ran

Today I ruan 20km Today I ran 20km

Today I ruan 20km Today I ran 20km

Today, I ruan a distance of 20 km. Today, I ran a distance of 20 km.

Today I ruan 20 km. Today I ran 20 km.

Today I ruan 20km. Today I ran 20km.

Today I ruan 20km. Today I ran 20km.

You're describing something which already happened in the past, so you should use past tense.

I feelt pain in my leg when I amile I was running. I felt pain in my leg while I was running.

I feel pain in my leg when I am runningMy leg hurts when I run. My leg hurts when I run.

What you wrote isn't incorrect, but this edit makes the statement a lot more natural

I feel pain in my leg when I am running. I feel pain in my leg when I am running.

If you always (habitually) feel pain in your leg then this is correct. If it's about the specific moment when you ran 20km then it needs to be in past tense. "I felt pain in my leg when I ran."

(I feelt pain in my leg / My leg felt sore) when I amwas running. (I felt pain in my leg / My leg felt sore) when I was running.

"I felt pain in my leg" is grammatically corrected, but "My leg felt sore" is a much more natural phrasing.

I am sleepy .. I am sleepy ..

I am sleepy ... I am sleepy...

Ellipses are 3 consecutive dots (...)

I am sleepy ... I am sleepy...