I wrote this
Serial.print("Led has been turned on ");
and the result came out like the picture below.
After trying a bit I found the solution, and that was so simple. If you want to print something in the same line then just use Serial.print and if you want to print something in a new line then use Serial.println.
After using this
Serial.print("Motion has been ditected ");
I got the result below.
I thought it would be helpful to share. :)