Answer:
The letter S is added to pluralise most words in the English language. eg. Letter to Letters Word to Words and Language to Languages. But I am a word that is pluralised with the addition of the letter C.
I do not contain flesh feather or scales; yet I have fingers and thumbs.
In many hall ways you would stand if not with me in hand.
At night I come without being fetched, and by day I am lost without being stolen. What am I?
I plow and plow but never sow.
What is full of holes but still holds water?