When he tried to sit up, something held him back.

After a while he tried to sit up, but could not.

He tried to sit up, but something held him back.

Just try to sit up and keep your head still.

She tried to sit up but he would not let her.

After a moment he tried to sit up, and they let him.

He tried to sit up, but his head felt light.

I tried to sit up and found it an effort.

He tried to sit up, but could not do it.

She tried to sit up, but it was no good.