to write with.
If you are referring to the phrase "To serve a purpose" then it would mean to give a use for. For example, A pencil holder cup serves a purpose to a pencil... the pencil give the holder purpose and that purpose is to hold the pencil. Basically it means, that something has a use... there is a reason/intended use for this thing.
The purpose of the pencil invention is to write down letters to form words.
To hold pencils
For Shading your drawing
Home Depot
what is original purpose for the dryer. by xavier jones
His original purpose was to get to india for gold.
Estevanico's original purpose of his journey was to search for gold
to open the carbon rod inside the wooden body of a pencil, to use for drawing and writing.
The original purpose of facebook is to communicate our friends and to see the information of of your friends
Their original purpose was to protect their community
Maybe the original purpose was to record events or to keep records of possessions etc. But the ultimate purpose of writing is to communicate.